Well all except the part about addiction, but you can't win them all! I did, however, learn why I cannot drink coffee after 2pm:
"As someone with a background in physics, I was delighted to find out that the amount of caffeine in a person follows a half-life curve. Briefly, if you drink 300mg of caffeine, five hours later there will be 150mg left in your body. Five more hours later there will be 75mg, five more hours 37.5mg and so on."