I agree with you.
Well you have heard people say that some people.could have depression because they were.always laughing. I said it to myself over and over. That I couldn't ever got depressed. How fool I was.
But its not certainly who We are. I can be and so many different attitudes. And specially.when I'm not feeling so bad I can be a nice person. I just can't control when it comes. And as you live with it a good part of your life, at least in my case, it starts to play a big role in the personality others say I have.