There's now a website which can solve all your mental health problems of doubt and depression.
Joy. Consider me cured.
It's a little dorky and British and a tad bit too survey-based for my tastes, but it's interesting. The basic premise is that unhappy people interpret events and feelings with a negative bias and happy people interpret them with a neutral or positive bias. Which makes sense, I guess.
The weird thing with me is that I think I used to be pretty firmly in category B. Things didn't bother me, and, if something really bad did happen, I always seemed to think it was unchangeable so there was no point in worrying about it. I took criticisms well, or at least I ignored them, and that seemed to be ok. I was also genuinely happy with other people and was able to forge a strong group of friends.
What changed? I do not know.