When you want to go to bed early, don't drink a pot of caffeinated green tea after dinner.
Otherwise, you might find yourself lying awake with your Better Half at 2 am, playing with your newly-found PH testing strips to wear you out. And when you find yourself shouting, "Aha! My saliva is more alkaline than yours!" you realize that you are totally fucked for work / midterms the next day.
I am so. Freaking. Tired. I never want to get that friendly with 3 am on a weeknight again.