It used to be 65 when you went into retirement. Before that, when you got into your 50s, you were getting older.
I think it's necessary to identify with anything - with any character you play, there's got to be something in common, so you can link up to that person, even if it's like one tiny thing. But it's equally fun to play somebody completely different, and trying to find what that thing is to make it.
As a child I was very involved with sports and I knew at age 9 that I wanted to be an Olympic champion.