Magic of the internet, my friend. Though personally I don't see pompous egotistical ass and understanding to be mutually exclusive.
Mine would probably be that even though English is my best subject in school and I generally use grammar properly when writing, in conversations I swear constantly and take forever to think of specific words that I want to say sometimes.
Hmm. One notable one for me is that I am good at math (did quite well on the math section on SATs and ACTs, as well as getting into the advanced math curriculum in high school) but I hate the living shit out of the subject.
Another one that might fit the topic is that I love to make people laugh and many people tell me that I am quite funny, but I am horribly uncreative, so any attempts by me to create comedy (be it written or comics or what have you) come out quite uninspired.
On here people probably know me as a motor mouth who has something to say about everything, but in real life I'm actually pretty quiet. I have tendencies to talk but in reality I'm pretty darn shy around large groups of people. I'm a very solitary individual, almost a recluse
Let's see. Something like that about me is:
My name is very simple, but I'm a very complex and quirky person.
Also, I'm very neat and clean, but I chose to have three dogs and a cat. Haha. I have a very big heart for animals. So it's a never-ending battle on my end, with only the vacuum as my weapon.