There really isn't supposed to be a coherent plot; it's all about the characters. I didn't think much of it myself until I watched it again a couple years after it came out. I love the dialogue because it sounds natural with sentence fragments and incomplete thoughts galore, as opposed to the very wooden dialogue of someone like Kevin Smith. If you watch it enough you'll pick up all the phrases that the Dude hears and then later misuses i.e. "A young trophy wife, in the parlance of our times..."
