When Do You Know....

WHen do you know when you're single. Is it after the disagreement and they don't call for a week, even though they didn't call the whole week before as well? Is it when you just stopped hurting and caring? When you finally look at others of the opposite s*x, and not only feel an attraction, but want to holla at them as well? When do you know?
Also can it be over with out there being an official conversation? Is it right for one just to assume because actions (or lack there of) speak louder than words? When and how do you know? Cause...I don't know.