This is a long-standing psych theory. A scammy self-improvement site is running ads based on it at the moment, which is what reminded me. The general idea is that we all have some pretty obnoxious and damaging characteristics, which are extremely deep-rooted in childhood. Jung called it a 'shadow' to allow for the fact that most people prefer to ignore their darker sides.
Jung himself went off on long retreats to commune with his shadow, but the therapy I did was aimed at learning to understand and acknowledge these characteristics, negotiating with them if necessary to keep our lives on track. I can't say I'm brilliant at that part, but at least I know who Dark Garlic is.
So here goes (non-exhaustively, I'm sure):
I procrastinate to the extent that I'll forgo things I'd have loved if I'd only got around to them This comes from fear of doing stuff wrong, for which I was often punished as a child. Maladaptive perfectionism.
I'm heavily prone to addiction. This is avoidance, an adult expression of the daydreaming I did as a kid to escape a toxic atmosphere. I use addicted behaviours or substances to smooth over discomfort.
I used to lie a lot. I stopped that. Nothing massive, but I felt I wasn't interesting / had nothing to contribute unless I jazzed things up.
I would be horribly grabby if I let this part of myself run wild. We were poor when I was small, plus my unlovely Dad took pleasure in telling me I couldn't have things. Food, money, clothes, everything ... my sense of "I want that, and I must have it now" is ridiculously intense. I'm always bloody negotiating with it!
I'm one of the world's great optimists, really good at seeing the best in people and situations. I'm also secretly pessimistic, cynical and suspicious (hello again, Dad). It comes out in my humour, which is sarcastic and often unconsciously cutting. I'm trying to keep the sarcasm and lose the sharp edges - work in progress.