A Great Math Joke

I was reading my friend Ryan's comic over at www.qwantz.com and I just saw the funniest math joke I have ever read (Disclaimer: This probably will be very unfunny unless you have taken a calculus class). Here goes:

So there's this party right? A party of functions. All the cool functions are there: f(x) = e^x, f(r) = pi x r^2, f(i) = i^2. Even some old school guys like abs(x). Anyway, poor e^x is over in the corner, all by himself. Well, his good friend, 2^x comes over and says, "Why don't you integrate yourself into the party?" And e^x says, "Why? It won't make any difference."

I laughed really hard when I read it. Also, this is day 4 with the illicit flatscreen.