A closer look

The defining catchphrase of 2010s nerd culture is rooted in a terribly unfunny office prank. Writer Stephen Engel used to play practical jokes on his co-writers, like taping a grapefruit back together after hollowing it out, and yelling his custom catchphrase when they fell for it. The writers eventually just forced the word into Sheldon's dialogue, proving that sleep-deprived rooms will weaponize absolutely any inside joke for a paycheck.