[burntroots]

Which is exactly why I respond with "I just don't." To which people usually shrug and move on. Every once in a while I get somebody who is curious or somebody who wants to be an asshole. With the former, I make a joke. With the latter, I change the subject.

[kelnos]

That's fine; you've decided that you don't want to talk about it. Other people are fine with talking about it.