Unfortunately this question does not involve any llamas. Very sorry. I can give you a picture of one if you like. [For the record, the LW's subject line promised a question involving llamas, so before you think "Well, LW, what you're doing wrong is being insane," this line actually did make sense in context.]
But anyways, I'm encountering a pretty general problem and I don't think I'm the only one who feels this way. It's just that no boys are or ever have been interested in me. Like, at all. I know it's not just shyness because the boys I know talk/flirt with to other girls frequently. Also, there are certain things guys do when they're interested in girls (like talk to them, or if not, be really super attentive whenever they're talking or doing anything) that I've seen directed towards other people but never towards me.
So I guess my question is, what would cause this situation? Are there any major turnoffs that guys just don't like that I might be expressing? Why are they all going for the same girls?
I feel for you, Sparkler. I was the same way for a while in high school, and there's a good chance you're making some of the same mistakes I once did (please don't feel horribly offended by this, since I'm always talking about how Past Jono was the King of Disasters). But Present Jono understands these things a lot better than Past Jono did, which is good, because you wouldn't have wanted to deal with that guy. This way, I can actually give you salient advice instead of just stuttering a lot and then somehow spilling coffee on you over the internet. Here are two pieces of good news for you, both of which double as dating advice.
Good News #1: It's fairly easy to make yourself more attractive.
Someone once asked me if boys notice makeup, and my answer was that they do, but they often don't realize what it is they're noticing. If you were talking to a guy, and then excused yourself and applied makeup, when you came back he would not be like "Pardon me, Miley Cyrus, have you seen my friend? She's about 5'7" and this is the only thing I remember about her appearance at all."
But makeup is just one small thing in a whole category of attractiveness that pretty much comes down to taking care of how you look. One study set out to find which features were the most important in determining attractiveness; the researchers figured it would be unchangeable genetic stuff like having a perfectly symmetrical face. But then they were all like "Bwhaa??" because the most influential features, by far, were all things that you can manipulate, like basic grooming and personal hygiene. (Scientific Accuracy Note: the researchers were probably not all like "Bwhaa.")
I'm not suggesting that you should obsess over how you look, and I'm definitely not recommending that you slather yourself in makeup until you are unrecognizable. In fact, the stuff in the study that men found attractive tended to be pretty fundamental, like having a well-kept hairstyle that suits your face and wearing clothes that fit you well (not, like, a Catwoman outfit; just not a formless Hefty bag either). In addition to those things, though, it's important to carry yourself like you're proud of how awesome you are. Also, believe that you are awesome. That part is critical. More on that in a second, but I want to stress that standing and walking like you're confident literally makes you more confident. If you're frumping around all hunched-over with your head down, your brain is like, "Well, I have the posture of a person who sucks, so I guess I suck!"
Good News #2: A positive personality makes you more attractive.
Another study had guys look at a sampling of female body types and pick which ones were the most attractive. Unsurprisingly, they were like "Uhh, the supermodel ones. Duh." But wait! When these guys were supplied with actual personality information about the pictured women, their answers changed. If the women's bios said they had positive traits—friendliness, openness, stability—the guys found a much wider range of body types attractive. Conversely, when the researchers were like "Here are some mean crazy ladies," the guys were like "Hnngh, no thanks." Keep in mind that they weren't being asked whether they'd date these women or anything, just to gauge attractiveness. Simply being told that a woman had a good personality made the guys rate her as physically better-looking.
So my scientific answer for you is that you can make guys more interested in you by taking whatever steps you personally want to take to feel more attractive (e.g. don't wear makeup if you don't want to, but do wear it if it makes you believe that you are amazing). Feeling like you're super-hot will make you act more confident and outgoing, which is attractive in and of itself. But if all of this advice is just making you go "Darn it Jono I'm friendly and I know how to brush my hair, sheesh," then I have one last suggestion, which is to be more overtly flirty around guys you do like. A lot of potentially dateable guys are simply terrified of you (all girls, not you specifically). You said the guys you know have no trouble flirting with other girls, but my counterpoint is this: girls are a scary mystery. It's easier for a dude to be flirty if he 's already getting signs that the girl is going to reciprocate instead of laughing in his face. If you work on being cheerful and approachable, and then broadcast your interest more clearly to guys you are interested in, I am certain you will soon be swimming in boys (although not literally because that would be uncomfortable).