Yeah, too much caffeine (especially late day or at night) can definitely cause sleeplessness. I only drink one to 2 cups of coffee every morning but I'm sometimes really bad about drinking Iced Tea and Diet Coke all day long and end up with caffeine over-load! I have to force myself to cut back on the caffeine and sometimes make myself drink 2 bottles of water for each glass of tea or diet cola ... which is very hard.
