In an attempt to begin this letter with something resembling originality, I will kick it off with a few interesting factoids: the "pound" key on your keyboard (#) is called an octotroph. Celery has negative calories. Ants never sleep. Ever.
Now that that's out of the way... there's a guy (I know, I tried). We're friends/acquaintances in band. He plays the tenor saxophone. He (unfortunately) has a girlfriend. He seems to alternate between being pretty much ignoring me and randomly saying hello to me in the middle of class. Once, during the PE dance unit, turned around, waved from across the room, and said hello to me. Loudly. (Of course, it might be because I was looking at him, but whatever.) Anyway, it's usually when I'm just walking by to go to my locker or something. So is he a compulsive greeter? Does he work as a Walmart greeter and likes to practice on his off days? Does he like saying hi to people, or is this actually significant?
And to kick off my reply with something resembling originality, I will offer you a few a few interesting factoids: Dogs are able to feel envy, and are therefore entitled to credit cards. The forests of Borneo are home to a "ninja slug" that shoots "love darts." A group of goldfish is called a "troubling." A troubling of goldfish.
Sometimes, while I'm waiting anxiously by my inbox for Ask Jono questions, I get one like this, and I wipe the sweat from my brow. "Phew," I say, "an easy one! I know the exact answer to this question, most definitely, because it is so obvious." And then a a piano falls on my head. A metaphorical piano of uncertainty. Because maybe my high school experience wasn't representative of everyone else's; maybe my normal wasn't the same as everyone else's normal. It's the same feeling you get when you discover that you've been using bizarre regional slang your entire life. ("This stuff is called soda? I've been calling it "fizzy bubble drink" for twenty years!")
So I put this question to some people who have the intellectual advantage of not being me, and they agreed with my assessment, which is this: almost nobody singles out one person to say hi to without a reason for doing so. And when you narrow it down to high school, and to two people of the opposite sex, nobody in the history of universe has ever thusly singled someone out without being (at least somewhat) romantically interested. If this dude were incredibly friendly with everybody, that would be one thing. If you were literally constantly staring at him, maybe his hellos would have the unspoken meaning, "Hello, stop staring at me, or else hello, I am calling the police!" But If there is a high school dude repeatedly saying hello to a high school girl, that's a sign of interest.
"Now, wait just a minute, Jono," you're probably thinking, "The ninja slug shoots love darts?" Yes, it does. It shoots potential mates with a calcium carbonate harpoon, which, according to the article, "could increase the slug's chances of reproduction." Maybe it does and maybe it doesn't. Maybe it's just crazy. Science apparently doesn't know. But the second thing you're thinking is probably: "But Jono, this dude has a girlfriend!" And I realize that; I didn't miss that part. Guys are more likely to want to date people while they already have girlfriends. Science says so. If you don't feel like reading that whole linked article, I'll summarize: guys and girls are equally likely to be attracted to their opposite-sex friends when they're already in a relationship, but guys, more than girls, are willing to actually date those friends.
I can't tell you what you should actually do about all this, because I don't know this dude's relationship status or your interest in pursuing him despite it. All I can tell you is that is a guy is greeting you over and over like that fairy from Ocarina of Time, he means something by it. And here, for the record, are some other things that indicate a guy's interest, listed in increasing levels of obviousness.
- Teasing, including the use of mildly annoying nicknames or drawing attention to dumb stuff you've done. The key here is the "mild" part. Someone who pokes fun at you because you once walked into a lamppost is teasing you; someone who repeatedly bonks you into a lamppost and then runs away with your purse is merely mugging you.
- Showing off for you. I can't theorize on how one would show off in band; I was so terrible at the trumpet that every time I picked it up, I expected the ghost of Louis Armstrong to stride into the room, glaring at me, and wrench it out of my hands without saying a word. But maybe this dude plays the saxophone in a particularly seductive way when you're watching? Like... playing the saxophone without pants on. I don't know. But showing off is surefire sign of interest.
- Noticing stuff about you. Most of us are pretty dense, and our perceptions are limited to things like "I am hungry," "I see a hamburger," "Now the hamburger is gone so I guess I ate it." A guy who remembers things you've said or notices details about you is almost always into you.
- Getting pouty when you hang out with moderately attractive guys or talk about boyfriends or whatever. Casually mention that you are dating a celebrity and see how he reacts. Make it some believable, middle-tier celebrity, like Ant-Man.
- Giving you any kind of compliment. Guys don't actually have any idea if your skirt is nice or your haircut is good. None whatsoever. Any implication that they think these things is flirty.
- Asking you to have coffee, or study, or any other activity. This is a date and it is always a date even if you think it's not a date. Everything is always a date, forever.
- Putting his mouth on your mouth. Unless you are not breathing and he is a lifeguard, you are kissing. This is making out and you are doing it. It is a good sign that he likes you.