I've started noticing that I'm being more.... noticed, lately. Not me entirely, but my chest. Lately I've noticed that lots of people full-on stare at my tits.
At first I just wrote it off: ie - "that guy is a perv", or "that lady just wishes hers were bigger/smaller/whatever". Then I started wondering if I was dressing skankier all of a sudden. Were my tank tops too revealing? If so, had they been that way all summer? Why weren't people looking at me like that in June? Then it hit me. They were; but before I had contacts, I didn't know it.
Yet another great example of how perception shapes reality.