아는 거 확인

A: Do you know what you're doing? 
   - -잘 알겠지? (어떻게 하는지 알지?)

B: Don't worry, I've been there.
   - 걱정 마, 무슨 말인지 충분히 알아.

-> I know what I'm doing / We have all been there / Been there done that