We take for granted that caffeine is a drug too. When I never drank any caffeine, I'd get a buzz (shaky, heart pounding, sometimes sweating) from a single mountain dew, which has I believe 54 mg of caffeine in a can. It actually worked like the drug it is, and helped me stay awake for those long nights studying in vet school or long drives. You build a tolerance quickly (days), hence the withdrawal headache if you don't have it. So yes, I can see how 2 huge Monster drinks could cause a 14 year old that never drinks any caffeine to have issues.
That being said, I do like the occasional energy drink..I prefer Rockstar punched which has 240 mg, but mainly because it's super sweet and tasty and helps me stay awake longer on my days off
