I mean, don't get me wrong, I love Alan Rickman. But I recently started playing the new Harry Potter "Mystery at Hogwarts" game and I came to the realization (because I OBVIOUSLY don't have better things to think about) that Snape should only be 23/24 in this game. He should have been 31 at the start of the Potter series, but Rickman was in late 50's. I know life was difficult in the Potterverse but come-on, a 31 year old does not look 50.
I'm sure the reasoning was that they wanted bigger names in the movies to get more of a draw, but surely there were actors in their 30's who could have played the roles?