I get irritable and experience melancholy when I'm over tired. Sometimes if I can't sleep I'll watch a movie I've seen tons of times and it relaxes me enough to fall asleep.
Peace, I drink two cups in the morning, and may have one at the coffee shop one evening a week or less, but I drink Diet Pepsi late afternoon/early evening, on some days. I'm going to experiment with it, and see what happens if I have a 3pm cut off. I only drink one 16 oz decaf bottle, but I think it must still keep me awake.
The night I go to the coffee shop, I'm awake all night, and I only have one tall one. I must have a high sensitivity to caffeine, even decaf, which still has a little, I think.
Don't no Carissimi. Hard different theories on it. In general I don't drink soda at all. Very rare that I do. I drink lots of water. And take vitamin and mineral supplements.