Hat's off to me?

Hats are "in".

Hat's are all the rage.

The cat looks great in a hat.

So my question is, "Why do I have to take my hat off in class?"

I mean, is it an exercise in humility for everyone to see my hair looking like I just got out of bed?  Here in Montana, a hat is crucial. On any given day you could be rained on, snowed on, sunburned, or windswept. Not to mention the below-zero temps. 

I decided to look into it. The Bible says in the Old Testament that women should cover their hair and men should not. The reasons were more to prevent other men from lusting after their wife.

Customs and courtesies of the military mandate that everyone take off their hat in the presence of a superior.

When I was a kid, the boys had to remove their hats indoors, but the girls didn't. (although if you tried to keep it on, surely someone would yank it off your head just to get a laugh - up through 12th grade)

I posted before about leaving my hat on in the cafeteria of  my son's intermediate school and the vice principal asking me to remove it.

My classmates in college wear hats in class - male and female alike.

I found one article on the web that discusses hat etiquette: Andy

I don't care about fashion or if people think I look good or bad in a hat. I don't care about what people think about me in public buildings in a hat, but school's a little different. I'd like to know, what's "correct" historically in the US, what's polite to my instructor, what sets a good example.  Have things changed in the 2000's? Even though I feel like I'm being rude, should I just do what I want and  be comfy in my hat whenever I feel like it?

Hat anyone?