Meh, if I didn't eat/drink/wear/use everything that is supposedly "bad" for you I'd be dead...actually no. I wouldn't have been born...hmmm, then
again, neither would my mother because having sex can cause cervical cancer in women...
I used to drinks LOTS of coffee back in my programming days, but I seem to have developed a sort of allergy to it. Now any more than 3cups a day and I
get heart murmers...which is nice
In moderation it's an awesome drug

Increase concentration / ability to remember, give you a lil pep up & put some bounce in your step etc