The line comes from Stewie Griffin, the baby of the Griffin family in the animated sitcom Family Guy, created by Seth MacFarlane and first aired in 1999. MacFarlane voices Stewie with a distinctive upper class accent that has made many of his short complaints highly quotable. Clips of the character have circulated for years as reaction sounds on soundboards and in short form edits, and this resigned one-liner fits the same pattern. It endures because it sums up instant regret in four simple words anyone can reuse.