I think that sometimes you just don't know how to act because you changed for someone and you spent so much time changing or having been changed that you can't quite remember how you were before.
You can't quite remember certain feelings or certain reactions;
You hestitate on things you should say and say jokes you maybe shouldn't have.
That's why its harder to forget someone than to get over someone.
You're almost stuck in the mode where you're used to knowing how someone would react to you or something you say or do.. it's natural.
Maybe I'm just making excuses for someone not acting on something.
But that's how I see it.
Just.. Don't lose who you are.