Am I going about learning to draw the wrong way? I've looked at drawing books many times over my life. I've never been able to draw worth crap. Even when I try to doodle all I can seem to do is make geometric shapes.

Recently, I acquired some books on figure drawing. Don't ask me what I was thinking. I can't even draw a cardboard box and I'm buying books on how to draw people.

I just can't seem to understand the craft. Everyone seems to view it as intuitive. To me, its not. Things in the real world aren't 2-d, they're 3-d objects. I'm not making a 3-d object when I draw, I'm making a bunch of lines on a 2-d piece of paper that will create the optical illusion of being a 3-d object. And yes, shading has been unfathomable to me. I just can't imagine how anyone could figure out where the shadows fall on something. Funny enough I've found sculpting far easier than drawing. Too bad that isn't cheaper to get into.

Anyway, the way I've been trying to learn is getting drawing books and doing what they say. What I make with those doesn't look that great, but at least its recognizable for what it is. I acquired a book on drawing dragons a few years ago, and I did do better than usual with it. Though I lost interest after making 2 drawings (one of a dragon's head, the next being a full dragon, the book has dozens of pictures it wants me to replicate).

But is this how I should be learning to draw? I rarely draw. Yes, I do art, but I've always favored the written word. Which was mostly because I can't draw worth crap. Written descriptions is the only way I have to give people an idea of what's in my imagination. But back on topic. Is this how you learn to draw? How long does it actually take to get good? I'm old enough now where I don't see the point in trying if its going to take me a decade or two. I'll probably become arthritic before I succeed if that's the case.

Oh, and I've always had crap dexterity. For me even using a ruler is somewhat of a challenge. I'm lucky I can even write. And when I do, I often have to erase and re-write things just to be legible. Which is why I don't like writing in pen. Pens are bad when you can't complete more than 2 sentences without making a mistake.

edit: I guess I need to elaborate on this. I don't like doing this when there's already so many answers, but oh well. I'm not really looking for a hyper realistic style. I bought two books to help me. One teaches anime style, the other something fairly realistic. I was looking for something in between those. I guess the best way to describe it is low in detail, like a cartoon, but without the exaggeration or odd features (such as characters having chins that end in a sharp point, or having eyes that are taller than they are wide).

Another problem is I just don't like the way pencil shading looks. It always ends up too dark and makes the image look...odd. I actually prefer my images without shading. Though that may be because I'm only doing line art so far. The shadows probably wouldn't look so dark if my illustrations weren't all stark white.

And I don't have a collection of sculptures laying around. I just found things like paper mache easier than drawing when I took that art class in high school. I only drew two 'realistic' pictures that I was proud of. One was using the grid method (over someone's drawing though), and the other was my backpack, which my teacher berated for its lack of color, even though my backpack was pitch black). I ended up dropping art 2 due to her not seeing any of us as even remotely decent.

As far as my art style goes, honestly, I'm fairly happy with it. I think it still looks a bit too cartoony in terms of proportions, but I'm aiming to fix that. And of course the lines are really jagged and not very precise (though that did improve slightly when I started drawing sketch rather than copy paper) Oh, and I'm a fan of traditional animation, so I honestly before a cartoony look anyway. I was mostly looking into drawing superheroes in fact. I may even do my own webcomic.
You say


  Things in the real world aren't 2-d, they're 3-d objects. I'm not
  making a 3-d object when I draw, I'm making a bunch of lines on a 2-d
  piece of paper that will create the optical illusion of being a 3-d
  object.


and you are absolutely right. That's what drawing is.

If you want to start thinking of 3D objects as 2D I suggest you  use only one eye when you draw or generally examine objects.

You can also take pictures of objects and draw from them (with the help of a grid on top, if needed). Or, better, place a grid frame and draw looking through it (this technique was previously used for acquiring accurate perspective, but I think it will work well to get you to think of 3D objects as flat):


*try it for smaller drawings though (A4 or A5) and without grid on the actual paper

Getting familiar with the basics of perspective would also help a lot.

Where shade falls shouldn’t be too confusing to you if you generally think of objects as 3D. If you don’t get too technical about it, light beams travel straight from the source of light and illuminate the surface they fall right on. The rest is in shade.

About sculpture, it is not necessarily an expensive undertaking. You can dig and refine your own clay. Plaster is relatively cheep too.