When I was very small, we had a chipped mug in an unusual rounded-square shape that featured a cartoon of a man with glasses and a dyspeptic expression, slumped in a chair and saying wearily, "I am so smart I make myself sick." (I Googled the expression and found it in a programmer's collection of geeky tag lines, but no source.) I loved that mug, insisting on drinking my milk from it and on numerous repairs as it was injured, until it was a patchwork of glued porcelain.
It's hard to say why I found it so appealing. Part of it was the funny little man, but the other part was the notion that there could possibly be anything wrong with being smart. Smart was good. Smarter was better. And as I started reading at three, and was widely praised for doing so - somewhere, there is a reel-to-reel tape of me declaiming from Green Eggs & Ham, squeakily - it was meta-funny that I could read it.
I also frequently heard the expression "Nobody likes a smartass," though generally in jest. Which is demonstrably untrue, especially if you've ever seen The Aristocrats.
But according to this Times article, it turns out that from an evolutionary standpoint, it may not be such a good idea to be smart. You really just need to know enough to survive better than others of your species. Too much learning can slow you down, especially if you're a fruit fly.
Unfortunately, I'm not very good at playing dumb. Nor has it ever seemed that would confer an advantage. But maybe the world might seem a touch less nauseating if I did.