고 까먹다

do it and then forget

-고 chains an action to 까먹다 "forget," so the thing gets done and then drops out of mind completely: 그냥 기부하고 까먹고, 내리고 까먹은 거야, 프리 데뷔를 하다 보니까 찍어 놓고 까먹어요. Leaving something behind is the classic case ([오자마자 의자에 놔두고 까먹었음] 내 핸드폰을 네가 갖고 있네?), as is setting something up and forgetting you did ([오프닝 시켜놓고 까먹음]). Several of these are captions poking fun at the person who forgot.

Register: casual; often self-mocking captions