Haven't really noticed it affect me in terms of energy levels, but if I go a long time without drinking any tea (which I usually have 4 or 5 times a day) then sometimes I end up getting a headache. Not due to dehydration (I make sure I'm still getting enough fluid, but just in the form of cold drinks that contain no caffeine). I don't feel like I'm addicted to caffeine but I probably am and I guess that's the side effect!

Other than tea I don't think I have anything else with caffeine in. I don't like coffee or fizzy drinks, but like I said I tend to have 4 or 5 cups of tea per day!

Nope :( used to work at a coffee cart thing and I once made 4 shots espresso and drank it in two gulps (waited for it too cool), nothing.... it was 7 am, and I hate coffee but I was desperate.

Caffeine seems to affect me more than other people.

I don't like to have it past 1 or 2 or else I might have trouble sleeping.