A thorn in my flesh and a plank in my eye

I think we all tend to think pretty highly of ourselves. If you don't, then you're lying. I was reading an article online that says in on survey, a large number of high-school seniors were asked how they get along with others. Less than 1% ranked themselves below average and 60% ranked them selves in the top 10%.
How and why is it that we become so good with covering our many inequities with our few assets? It is written "the weak will become strong" and I don't think thats just a metaphor. Knowing where you are below averages gives you a better view of your abilities and where you need improvement.
Sometimes I feel like some of the best way's to see our shortcomings is find what shortcomings stand out most to us in others. I don't think my roommates (who I love) read my blog, which is fine because it gives me a chance to pull examples from my own life. I have this one roommate and he bugs the mess out of me with his persistence to be right all of the time. If I step back, I realize a lot of the time he is right, and the reason it bugs me so much is it because it points out when I am wrong. One more example: I have a friend who is incredibly spendthrifty. He buys expensive things at impulse, a lot. I immediately find myself thinking highly of my self when I compare myself to him because I live on a budget. This is kind of funny because what it means is money is my idol, not his. I think about my money way too much, and even though I budget it, I still spend it on stuff that I don't need... I just have places in the budget for it.
Last time I checked, there were 6.5 billion people on the earth, and if I'm say I'm doing better than average, thats 3.25 billion people who probably disagree with me. It's a humbling thought, or it should be.
Peace.
mike