I've heard this said by a few ex-Witnesses in my three years away from the organization, and have sometimes said it myself. Sometimes it is said in the context of, "I'd like to move on, but I just can't stop thinking about them." Well.
Could it not be that one of the reasons ex-JWs "can't stop thinking about" the organization -- and their past involvement with it -- is that they daily log onto this site, read about the Society and talk about them? I'm not saying that this is wrong, but just a reason why some are "unable" to move on. In other words, it's not so much that they can't move on, but that they won't move on.
I am a huge Chicago Cubs fan, but I don't think about the teams blown chance to get to the World Series (four outs away!) a couple years ago...and the gaffe by the fan which may have cost them their ticket to the big show. I don't think about it, but if I logged into a website every day which analyzed that game I certainly would think about it. Out of sight, out of mind. In sight, in mind.
I'm not saying that there is not a fair amount of processing that needs to be done by a former JW. There is much that has to be talked about. But, to think that one must constantly go back and re-hash the "awful past" and the "terrible Watchtower" seems rather silly, if you ask me.
So my point is: Don't think you HAVE to go through a lengthy voyage of "deprogramming" to be "normal" again. And don't think that the reason your mind gravitates toward the JWs is because it just does this naturally. It very well may, but feeding that thought by participating in ex-Witness discussions only makes it easier for your mind to dwell on past and present pains related to the JWs.
Take some time away from this board. It will change your perceptions of the organization and your relation to it.
B.