Chocolate is lower in caffeine than tea, coffee and coca cola. A one ounce bar of chocolate contains about 6mg of caffeine, whereas a five ounce cup of regular coffee contains over 40mg.
Decaffeinated coffee is not 100% caffeine free. When coffee is being decaffeinated, 2% of the caffeine still remains in it.
You can overdose on caffeine.
If you yelled for 8 years, 7 months and 6 days, you would have produced enough sound energy to heat one cup of coffee.