What Hit Me?

There was this little guy sitting at a bar, drinking his beer, minding his own business when all of a sudden this great big dude comes in and - WHACK! - knocks him off the bar stool and onto the floor. The big dude says "that was a karate chop from Korea."
The little guy thinks "GEEZ" but he gets back up on the stool and starts drinking again when all of a sudden - WHACK! - the big dude knocks him down, again. This time the big dude says, "that was a judo chop form Japan." So the little guy has had enough of this... He gets up, brushes himself off and quietly leaves. The little guy is gone for about an hour or so when he returns. Without saying a word, he walks behind the big dude and - WHAM! - knocks the big dude off his stool, knocking him out cold!!! The little guy looks at the bartender and says, "when he gets up, tell him that was a crowbar from sears."