I tend to notice when people are looking at me. Or, at least I think I do. When I feel like someone ia looking at me, I'll instinctively look back at them. I can't help it. Whether it's the first time or the fiftieth time they've looked toward me that day, I am compelled to look back. I can't make myself stop.
I know that some other people do the same, because sometimes I get stuck in this awkward infinite loop where I look at someone, then they look back, and then we both quickly look away, but then they look back again, and then I look back at them, and then we just seem to stare at each other again and again over the course of the day or night. Even though I know it's not just me, I feel very weird whenever it happens.