The list of problems that don't have their roots in a fundamental misunderstanding of how things actually are is a short one. The other night I was playing poker, and one of the guys at the table was a really bad player who thought that he was really good. He and I played a hand where I surprised him and ended up winning. He was furious, threw his cards at me, and mumbled for hours about what a bad player I was.
I've certainly played hands poorly before and gotten lucky and won anyway, but this wasn't one of those times. I knew what he had, I knew what I had, I knew how much money was in the pot, I knew what my odds of catching the cards I needed to win were, and I could do the math to figure out that it was worthwhile for me to keep puting money in. All he knew was that he had better odds than me going into the last card, and I won anyway.
The guy proceeded to lose a thousand bucks or so, and I bet that this is a regular occurrence with him. I also bet he has no idea why he's lost thousands of dollars at poker. He probably just thinks that it's bad luck.
A few years ago I had an issue with reality as well. I thought: hey, I'm smart, smart people make lots of money, but I haven't made lots of money. The easy solution to that sort of disconnect is to ignore it or blame it on bad luck, but a better strategy is to examine each piece and figure out which one isn't true.