I like this quote from Scott Adams (The Dilbert principle):
"People are idiots. Including me. Everyone is an idiot, not just the people with the low SAT scores. The only difference is that we're idiots about different things at different times. No matter how smart you are, you spend much of your day being an idiot."
It's a healthy point of view to have in mind, not least when you are the idiot. Which I definitely have been...