That’s how you know you love someone, I guess, when you can’t experience anything without wishing the other person were there to see it, too.
Of course, you never really forget anyone, but you certainly release them. You stop allowing their history to have any meaning for you today. You let them change their haircut, let them move, let them fall in love again. And when you see this person you have let go, you realize that there is no reason to be sad. The person you knew exists somewhere, but you are separated by too much time to reach them again.
I said never apologize for how you feel. No one can control how they feel. The sun doesn’t apologize for being the sun. The rain doesn’t say sorry for falling. Feelings just are.