One year can mean a whole lot of things. People can change, get fat, marry someone, have yet another heartbreak just to fall back in love with the same person. It can mean an addition to the family, whether its a 4 legged friend or another human. It can mean that you will get older, taller and wiser. It can mean that your summer love from 1985 won't love you in 1986.
x: "Dude...what happened?"
y: "Its been one year. I've changed."
x: "You're not you."