Well CV: All of the above are true. I grew a mustache in RVN to be different. When everyone else grew one I shaved mine off.
When I was on the SCUBA committee the team sergeant hated them and swire a mask wouldn't seal over one. I grew one just to prove him wrong.
Besides, they have an additional use as a ---- broom.
On anmother similar thought, our SGM in Germany looked out the window and saw a trooper walking across the courtyard with his hands in his pockets. He opened the window and yelled: "What's the matter soldier. Are your hands cold?" Without hesitating the soldier replied: "No sergeant major, I have them in my pockets."