Nicknames

What's the deal with nicknames? They're funny, aren't they? Especially certain ones. How did "Chazz" become a nickname for Charles? How did "Chuck" become a nickname for Charles? Charley's the only real nickname I understand for Charles. Is it because Chazz rhymes with jazz and jazz is seen as smooth and cool? Maybe. Chuck I just don't get. Why would someone nickname someone else after a type of beef? I mean, I have a friend we call "Beef" but that's because it comes directly from his last name. But Chuck? Sure, it sounds manly, but is that only because of Chuck Norris? If not for him, would people laugh at the name Chuck as being silly? I doubt anyone would dare tell Chuck Norris it's silly, for fear of being fatally roundhouse-kicked in the cranium. I guess he's the protector of that nickname. What about "Hank" for Henry? Really? How did that one spring up? I mean, the two things that come to mind when I hear "Hank" are "yank" and "hankie" (short for handkerchief). Neither of these is anything I would want to be associated with, especially a hankie, which is a nice name for "mucus collector that you shove in your pocket for repeated use."