I'm in my 40's and so are nearly all of my friends.
The picture I have on my facebook profile was taken earlier on this year.
The pictures my friends have put up as their profile pictures are so old, they have had to be scanned in as they were taken in the days before digital cameras had been invented.
I know for a fact that one of my friends has for her profile picture a photo that I took of her when we went on holiday 25 years ago - I kid you not.
Why do they do that?