Do not let the past define you

That is one of my favorite sayings.
Only problem I have with people saying this is, that most of the time, THEY let someones past define that person.
People change all the time, they grow and they learn from the mistakes that they do.
To judge someone for something they did in the past is not something that I would do, ESPECIALLY not if I was one of the people throwing that phrase around, and not having all the facts lined up.
What I'm saying is that, try not to live in the past.
Forgiveness is the best way to move on.
Don't assume that someone is the same as they were before.

Let him who is without sin cast the first stone.