Well, it is a personal choice with how person to be or not to be. I was extremely personal/privacy-revealing when I wrote my P.S., and it paid off well enough I think. I didn't really have anything to explain besides why I had such a 180 in my undergraduate to my plans now (Barely-science to full on "hard science") and of course, the reason why I took some of the "harder" weed-out classes at a CC (and ~5 years after I rec'd my 2nd bachelor's).
I think that if you have extenuating circumstances to explain or elucidate on, you should include them. Of course, like I said, that's really personal opinion based and some people will say that you don't need to get into all that personal stuff and you'll still be fine.
I think, though, it's a great opportunity to bring yourself to life from the pages and to give them a reason to say, "Hey, we should give this Delano guy an interview!"
