Maybe it's hard to see why anyone should care about a poem that is, in essence, a bunch of nonsense words strung together in verse. After all, it's not like we ever use made-up words, or make noises when we react to things, or enjoy tales of violent heroism? Right? Right?
So maybe your use of the word "gaaah" on the internet doesn't have anything to do with Lewis Carroll, but what about, say, your love for a good, simple story of good vs. evil? "Jabberwocky," despite its goofy language, is about facing your demons. It's a strange world we live in, filled with all sorts of unknowns, and every now and again you're bound to round a corner and come face to face with something horrible (metaphorically, we hope). But we all have "vorpal blades" lying around somewhere, just waiting to vanquish our awful foe. And when we do, it's awesome. We're awesome. And we go along our merry way.
By presenting in whimsical tones a triumphant tale of conquest, Carroll tells us that not only does good win out in the end, but that it will win out even if we're not taking things deadly seriously all the time. And that's refreshing, isn't it?