There are the certain truths that we have established ourselves. Over our lifetime we have defined ourselves through the way that people react to us and by comparing ourselves to others. It's through this process that I've realised certain things: I realised that I was male because I earn more than most my colleagues. I realised that I was white because a policeman hasn't stopped and searched me for no reason. I realised I was ugly when I broke the world speed-dating record (200 women in three minutes). I realised that I had a sense of humour because I often make women laugh (though afterwards they cry and shower for hours).
There are, what I like to call, "assumed truths". These are the "truths" that we don't want to know, we assume we know. For instance: Your girlfriend tells you she's had boyfriends before. The way she says it makes you want to ask, but also that you shouldn't. In your head you assume it's only two or three, they had tiny cocks and always wore a condom- You don't actually want to know the truth. You don't want the truth. YOU COULD'NT HANDLE THE TRUTH! The truth is; It's actually 28 guys, you're 26 and her "Yoga night" is 27 (downward facing dog indeed) , your brother is 28. She fakes all her orgasms with you but never had to before. Your sex face scares her. **Always remember, in affairs of the heart ignorance is bliss....oh and that Sarah Thompson is a dirty, dirty whore.**
You need to know the truth, all of them. You need to know who you are and what you're capable of. It will make you much more decisive in your social interactions. Confidence is bred from you being comfortable in your own skin. If you have established who you are and augmented this with certain ego-enhancing "truths" that you've been told be others, then you'll be a confident and fully functioning member of society - sadly for me, that's the inconvenient truth.