Like all of players on the Inner Playground, Smart and Stupid are inseparable. Wherever you find one, you'll find the other.
Smart likes to think. Alot. All the time. Smart likes puzzles and problems, challenges and debates, riddles and conundrums.
Stupid likes to blunder and muddle, to muck about nonsensically, to play with paradox and inconsistency; stultiloquy and nugacity.
Smart is easy to understand, predictable, logical. Stupid is basically impossible.
Stupid likes to get Smart dizzy, drunk, stoned. Stupid likes to get Smart to play with dangerous things and people. Stupid likes to get Smart to overspend and overdo.
Smart is not as smart as s/he wants to be. Stupid is not as stupid as s/he pretends to be.
Stupid is especially good at making Smart feel smarter. Smart can help Stupid feel really, really stupid.
Drugs, alcohol, overeating, overdoing - they're all pretty much the same to Stupid. They're all ways that Stupid can get Smart to relax long enough so that Stupid can get a chance to play. Sometimes, one or two drinks is all it takes. Sometimes, Stupid has to use everything at once.
Without Stupid, Smart wouldn't know what to be smart about.