How the hell do they not notice?

I work at a gym on the weekends. An unfortunate result of this would be seeing many people wearing attire in public that they probably shouldn't. Don't get me wrong, there's the occasional seven or eight that comes in wearing a nice pair of yoga pants, but for the most part, our clientele is fairly old. My desk at work is situated directly behind the elliptical machines, specifically the high-stepping elliptical. I try not to look, but it's hard not to notice that there's usually an ass in my line of sight when I look up from whatever I'm doing to distract myself. Often times, there are pants stuck up the crack of said ass. I see this more than I'd like to admit, and every damn time, the person doesn't seem to notice. An hour of cardio and pants up the ass for the duration. What the hell? How do they not notice that? I don't know about anyone else, but I tend to notice a wedgie right away when I'm exercising. Another thing I notice plenty of are avoidable muffin tops. I'm not ragging on people for them in general; I'm not in the best shape myself. I just don't get those who are completely oblivious to them. They'll be sitting there, with a massive love handle hanging bare out of their shirt, and they don't even seem to notice! Again, isn't that uncomfortable? Don't they feel a draft? The worst is where they've let it go long enough where a bit of their ass crack is showing. Christ, pull up your pants! Or pull down your shirt! I don't know, just figure it out; think of the children! Anyway, what are some unflattering or uncomfortable-looking things that you often see that those sporting them seem oblivious to? Generally speaking, not just at the gym.