People notice, in the case of hairstyles and beards, they just figure everyone else will mention it, and you'll be sick of hearing about it. They think they'll be the one to act cool and be the the one "normal" person who isn't yammering on about the change...
Of course everyone's thinking the same thing.
When you've got a disability, like a wheelchair or scooter, people have a nasty little loop running in their heads.
"Oh, guy in a wheelchair, three o'clock. Don't be rude, don't stare.
Maybe I should make eye-contact, so he knows I'm acknowledging his personhood, smile, or say "Hi" or something... No. Wait. He's going to think I'm just saying hi because he's in a wheelchair.... Uh, now he's going to think I'm ignoring him because I think he's a freak... No. I should just ignore him equally like everyone else so I'm not making him feel wierd... AHHHHHHHHHHHHHHHHHHHHHH!"
Lather, rinse, repeat.
I exaggerate obviously, but some semblance of that is flashing through most non-disabled peoples minds for at least a brief second when they see you.
If you can be philosophical about it, you can turn it around into a positive and realize that this happens because the majority of people are decent, and are trying to be decent, and just don't know what to do.
It's hardly comparable to a permanant disability, but in high-school I had a bad bout of Alopecia, (stress, depression, allergies, the doctor didn't know why...) and I got a really odd bald spot, sort of a "Friar Tuck" look that kept growing to about the size of a softball, except it was at a funky angle on the side of my head. I felt the difference, and it was amazing. Everyone was nervous as hell around me, staring, or pointedly not staring... It was only after steroid injections started growing my hair back I learned that everyone thought I had cancer.