Two uses turn up here. On a past verb it asks yourself about a memory, as in did I even ask, or was booking flights really this hard. On a present verb it becomes a curt then just do it, which is dismissive or annoyed: then clean it yourself, you should have done it secretly, either get on or get off. Tone tells you which one you are hearing.
Register: casual; the then-just-do-it use is blunt and irritated