Why Is It That When Someone Smiles at Me I Don't Smile Back?!

Honestly, even if it's this guy who's way older than you who looks to have been staring at you for a while, all I do when I catch someone smiling at me, I just sort of walk by. Like adults, they smile at you all the time(well, some of them do). Kids just make weird faces at you. And babies don't know what to think. But when someone smiles at me I just get all freaked out. Sometimes I can manage more than a grimace back, but most of the time I just stare, deer-in-the-headlights like. Like this guy at Whole Foods, (Dan, we'll call him, though I know his name), he's really nice and he's so awesome I'm going to put him into one of my stories as the awesome uncle, but I turn around after we check out and he's smiling at me, and it's really kind of freaky. I was like "creeper" though I could have smiled back and made the entire situation end. But I didn't. God, I always realize these things too late.

Strange Walmart Experience - No Sunglasses

I know, I know. When I say "strange Walmart experience", you think I mean some person rammed through the wall in their Hummer or a bear was dressing itself in little girls' clothes, but it was semi-normal for those who have seen really weird things in Walmart.
   So I ran into my friend's mom and his little sister in Walmart, and our moms were all talking and his mom said "Oh, he's here a few rows up." About seven minutes later he finds us and throws up his hands, a exasperated look on his face, like "Starting the party without me? Really?" Usually he's wearing sunglasses when I see him(well, the past couple years at least) and he wasn't this time, and he almost looked like he had a completely different face. Like in a dream, how you know who a person is but they look nothing like that in real life. I was studying how his eyebrows were black with silvery edges in contrast to his blonde crew cut, and how I could actually see his blue eyes. He didn't really look at me for a while, probably just because it was awkward, what with being in Walmart and our moms talking about school and whatnot when all of a sudden he's looking right at me. I was looking back for only the first nanosecond before I composed myself and looked down the aisles and everywhere else, though in my peripheral vision I could feel his sky blue eyes searing through my head. It was really weird; my mom usually tells me if someone was "checking me out" and whatever, or I see it and try to avoid their eyes(especially if they're older than me by a lot, like at Whole Foods today), but this was really strange. I mean, I write about that kind of thing all the time, but it was really odd in real life, with someone I'd known for four years who had just been a friend, if even that. I had sort of been convinced that when we had seen each other at our siblings' school a few days prior he had been looking at me, too, but I couldn't be sure when the giant silver sunglasses covered almost his entire face. But today, he couldn't have done it without me noticing. I almost wanted to say "look, haha, I'm wearing my transition glasses and you've got nothin'", but I didn't because we didn't even speak a word to each other, except me chuckling at his already having an essay due a week into school, and his staring. Weirder thing is, it might have been a first time, so it was sort of awkward, but it was almost as if he saw me, and I didn't mind. I wonder now what he would've done had I looked back. I laughed at myself on the way home, reciting a line from Vampires Suck: "You're staring at each other in slow-motion". I didn't want to be a movie, but wow, that was crazy. My mom said he was just wondering at the red bug bite smack in the middle of my forehead, but I knew that if I had looked up, he would have been staring straight into my eyes.