the.com/smartness
The polished glow of a mind that knows it's shining, and won't let you forget.
means The quality of being intelligent, quick-witted, or sharply clever — and sometimes the stylishness that accompanies it.
from From Old English smeortan, to sting or cause sharp pain; the prick of a wound became the prick of wit, then the sparkle of being clever and sharply dressed.
Painful rootsSame source as a smarting sting or burn.
Dual lifeMeans both brainy and stylishly trim.
Smart aleckAleck was a 1860s con artist's nickname.