Sam Harris, in his recent article called The Fireplace Delusion, tries to make you feel what it's like to react to a cached belief being irreparably destroyed. Just incase you forgot what your apostasy (if you had one, of course) was like in its early stages.
What are some of the Fireplace Delusions you've come across in your days?
EDIT: WOODSMOKE HEALTH EFFECTS
Good article, but there's a huge difference between realizing that one's fireplace is dangerous and realizing that one's entire belief system is completely wrong. The crushing feeling of emotional loss that often comes with the latter isn't easy to replicate, and losing an "everyday" cached belief can't even compare. Nonetheless, having a cached belief broken is still good mental exercise.
(My personal reaction to updating about fireplaces: It didn't occur to me until now that fireplaces were dangerous, and at one of my former places of residence there was a pretty active wood-burning fireplace. After reading the article (and spending a few minutes fact-checking Harris's claims), I just thought "Huh, didn't know that. I'll avoid them from now on" and then went back to thinking about other stuff.)
My apostasy was nothing like that, there was a large sense of confusion, and the discomfort of holding conflicting beliefs while things resolved themselves but not loss.