Sometimes, when I start really forcing myself to speak Spanish, I start realizing how much of it I really don't know. Obviously, with more confidence, any language learner will enter into increasingly complex conversations and try to use increasingly complex sentence structures. Why have languages developed to be so complex, you might ask? Well, because certain ways of saying things have certain (different) connotations to them that require slight, subtle, or sometimes not-so-slight-or-subtle alterations of expression. Along the course of learning Spanish, for example, I have evolved to be able to say the same thing, but each time, more specific, with more personality.
Basic textbook Spanish
Tengo hambre. (I am hungry.)
Slightly more advanced texbook Spanish
Tengo mucha hambre. (I am very hungry.)
Tengo muchísima hambre. (I am very, very hungry.)
Tengo un montón de hambre. (I am really freaking hungry.)
Colloquial Spanish with a twist of humorous exaggeration
¡Ay dios, me muero de hambre! (Oh my god, I'm dying of hunger!)
¡Tengo tanta hambre que me muero! (I have so much hunger that I'm dying!)
I'm sure that there are some weird sayings that are pretty widely known (except by foreigners) that express hunger without even mentioning it. For example, if I were really, really hungry, I don't think it would be out of the question for me to mumble in English (to myself or to others), "Seriously, I could eat a horse." I'll bet there is something along those lines in Spanish.
To tie this all back in, I think there is the same feeling upon realizing how much I don't know in Spanish as there is upon stepping into a library. I realize, all of a sudden, how much information is in a library, and I start wondering, "What's the point? I'm never going to learn all of this, so why bother?" Entering a library can often be a sobering experience, don't you think? So is stepping forward into a different language, into the jumble and our of your comfort zone. It's scary. It's intimidating. It's embarrassing. It really is.