I've met jocks and stuff before, and for the first month or so of knowing them I actually believed they were a typical 'bully'.
However after a while I realized that a lot of their attacks on people (not physical, but rather just insults) were actually completely true of the person; but how they worded it was just different from how we would have worded it.
It's impossible to explain really, but that's how it was.
The closest thing that has come across my path as being as bully is a guy being more of a prick.
Constantly bragging about himself and trying to shoot everyone else down; but when we actually got a good (and true) jab at one of his faults he would instantly go into the defensive about how he was adopted.