[edited].

Your post is typical of many that I read; it’s a sequence of receiving certain information during your upbringing, finding out new information later, and being unable to reconcile the two.
What I don’t see in your story is any mention of testimony, which I think is a hugely important consideration. I know what it’s like to come across new information that challenges a lot of my long-cherished beliefs about things. But at several points in my journey, I have had experiences I can never deny, which have kept me in the Church.
That said, I know what it’s like to feel like the Church “system” simply does not work for me. In my single years I had those feelings very acutely, and I almost married outside the Church in an effort to maintain some activity in the Church completely on my terms, without the constant “supervision,” for lack of a better word, of an LDS wife. But even in those times, I could not deny things that I have come to know on a very personal, spiritual level.
With the exception of Grant Palmer, I rarely hear that kind of experiential understanding being alluded to by people who leave the Church. And for that reason, I find it hard to relate to people who leave based on simply weighing sets of information on some logical scales and following whichever side the scale tips to in their mind.
In my seeking, I have come across the usual troublesome topics of blacks and the priesthood, polygamy, the MMM, etc. but I have chosen to not put them on a scale to weigh against my understanding of the Gospel. Instead, I try to examine those issues through a lens that accounts for the frontier worldview of the founders of the Church, and the humanity of all our members, including the Prophets. Their humanity makes them worthy of my compassion and even forgiveness.
In that light, I don’t feel a need to analyze so much as I feel a need to forgive in response to a lot of the unfortunate things that have been said and done in the history of the Church.
I think that if I did not have a testimony, it would be easier for me to leave and then hang around, just out of curiosity. But I feel like, given what I know, if I were to leave, it would have to be an absolutely clean break.

I like the quality of the responses to this post, both from the believers and the non-believers. Were I to leave, I think all of the responses would apply to me in various degrees, but the strongest reason I’d stay engaged is that I love my Mormon friends and family members, and I’d stay involved in the discussion because of my longing both to understand and to be understood.

Geographically, I’m in the pew on Sundays. For that matter, aside from illness, work, or travel, I can count on the fingers of two hands the number of Sundays in my entire life that I haven’t been in an LDS pew for Sacrament meeting. By any of the standard measures (other than temple recommends), I’m a fully active member of the Church. But my beliefs differ very substantially from the content of the Gospel Essentials manual –and, fwiw, my spiritual experiences are not fully consistent with it, either.

I’ve come to understand the Church’s take on things as a conceptual model that is laid on top of the raw experiences of life. It accounts for lots of aspects of life, and it does a remarkable job of highlighting and interconnecting some of the most important aspects in important ways. But it’s far from the only way to conceptualize those experiences. And, with regard to other aspects of experience and life, it does a distinctly bad and harmful job of assembling and inter-relating those ideas. Sometimes I wonder which outweighs which, and whether that is even a useful way of thinking about it.

Could I walk away? If I were not fully connected to my family, which is quite LDS-centered, perhaps I could, but the conceptual structure of the LDS Church and doctrine would continue to shape my thinking, as it’s embedded in my mind.

In this context, I remember reading recently about a study of the brain that was performed on two sets of London cabbies. (You can google “London,” “Cab,” and “hippocampus” to find lots of references, if interested.) The hippocampus is apparently one of the key parts of the brain that sorts out spatial relationships. The size of the hippocampus was measured for a group of drivers who had just started the rather intensive training for getting a cab license in the labyrinthine streets of London. And the size of the hippocampus was measured for a group who had been London cab drivers for a long time. As I understand the study, there was a substantial difference between the sizes of the hippocampuses of the two gorups, the experienced drivers having larger hippocampuses than the newbies.

The study suggested the possibility that we change the structures of our own minds by engaging in particular types of training and learning, reinforcing some neural pathways, diminishing others, increasing neurons in one area of the brain, removing them in another.

If that inference is correct, it suggests that there could well be not just an “LDS belief” set, but an “LDS mind” set, as well — a structure of neurons and thoughts that develop and reinforce over time among those who live and embody (literally) LDS teachings and lifestyles. Of course, not everyone in a particular pew on Sunday morning is likely to have incorporated the belief set to the same degree. But for those who have done so, yet still find themselves “not believing,” it would be most unnatural — and perhaps physically impossible — to simply discard over night the neural wiring that they’d developed over the course of a lifetime.

On a more serious note, given the enormity of the problem of inactivity, it’s not surprising that the active membership has evolved an “affirming and comforting” cultural response. That is essentially denial. If denial becomes untenable, there are two options: 1. Admit what is happening and change, or 2. Admit what is happening and embrace a theological explanation for a smaller Church (“Great Sifting,” etc).

similarly, one can “leave” belief in core aspects of the Church while sitting faithfully in sacrament meeting each Sunday morning.

That’s where I am, and it’s nice to know that others are there too. I still attend for my wife and kids, but for nobody else. The Mormon church just doesn’t give me the ROI that it used to. About 8 months ago I started longing for more autonomy and freedom, and found myself getting out of callings, spending more time with my family, keeping more of the money I earn, and I found happiness in so doing. It’s a constant level of happiness – I had to strain to find happiness when I was more active in the church.

But to get to Steve’s point with this post – I think if I were to leave entirely, which is very likely at this point, I would also leave it alone and have no compunction about telling people that I was once a Mormon. I would even stand up for Mormons if I had to. Good folks. Who knows, maybe if the church demanded a little less from me I might find myself going all the way back.

My first reaction is that I don’t like the question. I suspect that many (most?) attempts to characterize complex phenomena in simple catch-phrases, such as lumping the diverse interactions of diverse groups of former Mormons under the simple banner “leaving the church, but not leaving it alone,” are bound to provide incomplete explanations. I’m not sure that it’s even a fair question to ask if we’re looking for an actual explanation. It seems to me that church members endorse the catchphrase (which is affirming and comforting) and thereafter lump together others’ behavior under it. I suspect that attempts to match actual behavior to the catchphrase are more likely to be eisegesis than exegesis.

But, be that as it may, the catchphrase does have some currency among church members. So it may be worthwhile to ask why some former members engage in the kind of behavior that active members would describe using the catchphrase (even if it makes the most sense to reject that characterization altogether).

I suspect that a major factor, not on your list, is the idea of reorientation. This takes place for at least two reasons.

First, for many former members, the act of discovering additional information about the church (JS polygamy or MMM or whatever) is itself a precipitating event in leaving the church. They leave, just when they find out the interesting stuff. And given that conjunction of events, of course they want to talk about church issues after they leave.

Compare it to, for example, the series finale of Buffy. As viewers, we’re in a sense forced to depart from the viewer relationship, at the exact same time that we receive a major influx of new information. Of course we want to talk about the new information, see what we think of it, discuss it with friends or family or whoever. That desire is not squelched by the end of our formal status as viewers of new episodes of Buffy.

The second reason is a natural desire to place old events and ideas into a new narrative. Again, we can illustrate with popular media. Say that you watch a movie with a major plot twist at the end. Say, Memento or The Usual Suspects or The Sixth Sense or Fight Club.

At the end of the movie, you’ll want to go back and watch it again. And as you re-watch the same movie, with a different understanding, different meanings become apparent. You say to yourself, [Um, spoiler warning, in case anyone didn't know this one] “aha, Ed Norton was really Tyler Durden all along! Now that part makes sense, but in a different way.”

I can’t speak from experience here. But my sense, having discussed religion a few times with former members, is that the same recasting takes place for many former members. That is, they undergo a process of reprocessing old understandings using new baseline assumptions, just as we watch Fight Club the second time through with new information and see things differently. And I suspect that that recasting is what is taking place in a number of conversations, that active church members view as hostile or threatening remarks that show an inability to leave the church alone.