Glancing through the Past

So lately I've been hung up about the past. I think about old friends; I look for them on myspace/facebook; I also have been reading my old posts from 3 years ago. I feel like i've changed so much. I used to be funny and witty, but I feel like I may have lost that. I feel like i've begun to stop finding humor in the world around me. It makes me sad. Everyone's life keeps moving forward, including mine, but I keep looking back and then tripping on things that are in front of me because i'm not looking where I'm going. I want a little of my old self. Is that impossible?