It is a bit strange that men can't shave their bodies IF they don't do certain activities. My roommates are still somehow unaware of what I am, so by the time I got rid of all my body hair, I was actually pretty surprised to hear nothing from them. Even one who is a total 'bro', has not commented in the slightest. I think people being so conscious of what they're doing, is what makes people pay attention... It makes sense! If you act nervous, people are going to sniff that out of you, and then go about trying to figure out why you're nervous, and then they may notice you suddenly have no arm hair or WHATEVER is the difference they weren't paying attention to!
I wrapped my arms around the back of the car seat, with my roommate behind me, and he didn't seem to notice, with my arms RIGHT there. They are not typically ones to remain quiet either. So I think people need to realize, a lot of people are really unobservant! I suppose the only thing is, if you have a LOT of hair, like gorilla hair, and suddenly it's missing, it's pretty apparent.
Those who crossdress, shifty eyes and nervous twitches, or nervous weight shifting, may just be the very thing giving you away, or making people look and figure out what's different. Act like nothing is different, and people's perception of you will not be different - unless you happen to come across a very observant person, or the difference is very major, like hair dye, wig, bras, nail polish, or going from really hairy to not hairy at all.