Practice, practice, practice. No, wait, hold your rotten fruit, I'm serious.

It's a bit hard to articulate, but I've been thinking a lot lately about the interaction between two human abilities: the ability to do whatever you want, and the ability to get better at something by doing it over and over. The second one sounds like the hard one, but really the first one is--most people never realize that they really do have full agency over their own lives. They're too used to ruling out possibilities according to someone else's heuristics, and never stop to examine those heuristics. If you haven't yet fully internalized the fact that you really can do whatever you want, I'm not sure what words would inspire that, but think about it.

As for the practice bit, again, people have this artificial division between "people who can do x" and "me." But all it really takes to be able to do most things is to try to do it a lot, ideally in a structured sort of way. The catch is that you have to be willing to do something you're really bad at for a while--as Go players say, lose your first 100 games as fast as you can. Or play 100 twangy horrible chords before you play a pretty one. Or screw up 100 math problems before the concept makes sense. But if you decide you'd like to have a certain skill, and have a good attitude about the necessary period of sucking at it, there's nothing stopping you from acquiring the skill.

The synthesis of those two ideas is quite liberating. As it applies to your case, you can learn as much as you like about whatever you like, including ways of reasoning and discrete facts and abstract concepts. There are also exercises that'll improve your brain's capacity to learn, understand, and remember. (I don't know a lot about that, but there are other people here that do.) And you can have as much of all of this as you want, limited only by how much time you can find for it. In short, yes. You have all the power you need to be as intelligent as you aspire to be; you just have to choose to use it.

On a side note, you should know you're not alone on the low-level-of-formal-education front. I'm a high school dropout and just started college a couple of months ago, in my 20s. A lot of the technical stuff on LW goes over my head--but, per the above, that's mostly because I haven't chosen to dedicate time to learning it yet. :) It's lower priority than schoolwork and other projects of mine, and knowing that makes me feel totally fine about not understanding.

(ETA: Okay, so this is my 2:30am level of eloquence. If it still seems like a good idea in the morning, I'll think about drafting an essay explaining the point in more depth, since, as I said, I've been thinking about it a lot lately.)