Should you survive a gunshot wound/knife stabbing/drive by/ getting hit by a car and still be standing, this phrase should be said, followed by a smirk. It is garuanteed to cause a massive drop in your attackers' morale, and they may even turn tail and run.
When emotional tension in an undisclosed relationship erupts in front of other friends, one can only comment with "What was that all about?'
Mark: Katie your hair looks great today.
Katie: Fuck off you souless twat.
Mark: Whatever bitch, suck a dick.
Katie: Not on your chode that's for sure.
Bob to Neil: "What was that all about?"
The previous person who wrote that it came from the musical "All That Jazz" is very wrong. The expression has been used for a LONG, LONG time before that show ever came out. I mean, people I know have been using the expression for as long as I can remember, LONG before anyone ever CONCEIVED of the show named "All That Jazz". It's probably been used since at LEAST the beginning of the 20th Century and probably longer than that. It's another way of saying "and all that stuff". It's a slang way of saying something without telling the whole thing, because telling the whole thing would be boring and monotonous.