Because I thought it would look cute.
Okay, that was the pixie cut which got me called sir at least once a day for months.
Actually, it looks better short on me. I have fine and oily hair, if I wear it long it thins out on top because I tend to pull it back all the time and I look like I’m 15 again. Last time I grew it long was for my friend’s wedding (bridesmaid, I had a lovely updo), and the following week it was all chopped off again. I do not have the time nor inclination to do all I would have to do to look good with long hair on me. I prefer beauty sleep to good looking long hair.
In my teens I would get a cut once a year, by the time summer rolled around again it would be to my shoulderblades and drive me nuts and I’d get it lopped off to just below (or above) the ears (depended on the stylist I got…). Now that I have an AWESOME hairstylist I get it cut every 3 months or so.