Maybe it's true that people don't pay much attention. Several years ago, I had hair past my butt. On a dare (I was ready anyway.), I got it cut into a bi-level - one side was at the level of my ear lobe, the other was just at my shoulder. You'd think at the very least people would have noticed that, wouldn't you? It was really pretty funny because of all the comments I'd always had about my gorgeous, long, curly hair. Then about 2/3 of them didn't notice when two feet of was gone. And that's a lot of hair.
At least they still recognized you!
From the middle of 7th grade (I was 12) until my last year of high school, I had been growing my hair. When I was 17, it was about waist-length.
Then, April of 2001, I got it cut to a chin-length bob. I went into school the next day, and in my chorus class people were commenting on the "new student."
Although I'm not sure if I'd put my contacts in that morning or not, which could've been another reason they wouldn't recognize me--I wear my glasses EVERYWHERE, and rarely wear the contacts.