The Funniest Joke EVER!

I heard this joke at work today and I literally LOL'ed. Some guy was at my office setting up our computer network, and he said something to my boss about being, "Green" and saving trees.. My boss responded with this clever line, "Yeah, I like to save the trees so that the deer will have something to hide behind."

Isn't that HILARIOUS?! Do you get it? I'm not even sure I completely understand but all I know is that I thought it was so funny... I hope I'm not the only one!