The rest of what I wrote wasn't really my full reasoning for that conclusion. I can only experience my own emotions, so I have to go with that. And I don't have any diagnosed psychiatric conditions, so I don't think it's that unfair to reflect on my emotional introspection. I never dictated anything other than that I have "doubts".

I don't have a specific reason why I think people aren't very good at assessing their emotions. It's a conclusion from an amalgam of my experiences with other people. People can certainly recognize if they are happy or sad, for instance, but I don't find they are very good at distinguishing between things like contentment and happiness. I've met lots of people who think that an absence of happiness is sadness, when in reality someone can be emotionally neutral.(the connotations around the word unhappy don't help) It's common for people to confuse depression for sadness. Personality and how someone can respond to emotion can mask their feelings, making them less obvious to both others and themselves.