Quitting tobacco is indeed very difficult--if there's anyone considering smoking, maybe go build a bong, but don't smoke tobacco. People need to know how addictive the stuff is. More addictive than heroin and cocaine, and even worse, it's so heavily advertised that people overlook the damage it has on people's lives.
The advertising is particularly scary. Since nicotine is such a powerful substance, tobacco companies can trigger a nicotine headache with very subtle and simple advertising. Since you'll feel like shit until you get you get your cig fix, it's very effective. Whoever posted the comment about clarity--the clarity they're talking about is that very fix. Clarity from the grips of the nicotine headache. The headache that never goes away.
So.. uh.. don't do it. Try something productive.. like LSD