Depends on the severity. Now a failed test, that usually doesn't last for long. I usually give it 5 mins tops

But for relationships, depending on how close you were to the woman, err, or man, give it some time. Maybe you could try "getting ON" something, or
someone.
I don't know it's possible to be 100% OVER anything. There's always those little remnants of memories lying dormant, haunting you whenever they feel up to it.