I read recently about a web site that used preset personal questions as a way for people to get their passwords back if they forgot them had done a little survey.
They checked the rate that people remembered what they had entered previously for two specific questions when trying to retrieve their password.
The name of your first pet?
The name of your first lover?
Surprisingly enough people who answered the pet question had a 100% recall rate, whilst the people who had chosen the lover question got it wrong 90% of the time. So people had no problem remembering the pet rabbit they had when they were two, but 90% of people couldn't be arsed to remember who took their virginity. Perhaps they should combine the two questions?
What was the name of the first animal you had sex (sorry, made love) with?
I'm sure there'd be a 100% recall rate on that one!