Well, they are and they aren't. I like the idea of memories, but I want it to be like TS2 was. TS2 only saved memories for the big things; got married, first kiss, new house, had a baby, etc.
TS3 memories are so stupid! I'm playing my sim named Keyo right now, and it's like this:
Keyo just went to the bathroom! Share the experience on Facebook!
Keyo just made waffles! Share the experience on Facebook!
Keyo just went swimming! Share the experience on Facebook!
And the worst part is, they are all popup messages! With TS2, the memory just saved without letting you know. Or they'd have an icon, if it was a big moment. This is too annoying!