All the time! But less and less as time goes on.
I think part of my problem was that I was looking for the perfect answer, the perfect solution, the perfect outcome! While I was looking for perfection, I was driving myself crazy because there is no such thing.
I've recently learned to change my outlook to this: I base my decision on all the knowledge that I have at the time, weigh the pros and cons on paper, and seek the best possible solution. It may not turn out to be 'the best decision' afterall, but it was the best choice at the moment. Sometimes that is the only thing to do.
Another thing I'm working on is 'what is best for me'? Not what is best for him, for her, for them, etc., but for 'me'! When you take everyone else out of the equation, it makes your picture a lot clearer.
Most of the men in my life, from father to brother to ex boyfriends have told me I am over emotional and exaggerate. They usually tell me that when I find out something about them that they've been hiding (as in lying to me)! Funny thing about that, huh? They get caught and turn it around to make 'you' look like the one that's at fault. It's called 'deflection', 'denial', or 'just plain annoying' if you ask me!!
You might 'forget' about how bad things were because that is sometimes how we cope with the unpleasantness of the situation. "It wasn't that bad"! "I wasn't really hurt"! "He really didn't mean it"! Oh yeah, I've been there and man have I done that! I eventually stopped lying to myself, because 'it was THAT bad', etc.
And about missing him, well, yeah....that is a part of it! Feel it while you feel it, but don't let it consume you. Life does get better without them.