For one, to see if I can (been drinking coffee since I was maybe 7 or so)

For two, because maybe I'd feel better or sleep better !

Pretty sure there is some caffinated tea leaf that is native to the USA.

Edit: Ilex vomitoria

You should try it - some people report various health benefits. Others report no effect. (and half from both groups are looking at what they care about and ignoring other evidence) Your doctors may have guidance on how it affects you.

I'm only asking for a 2 week trial. Then evaluate if it is worth going longer or not.

Caffeine is enjoyable to me but it affects my mental state a lot, in some ways negatively. In particular I feel less able to think about things holistically, way more tunnel vision type thinking. It's worrying that so many people use it every day and I make an effort not to.

I love my caffeine, as an undiagnosed but very high certainty person with ADHD. However, I like to go caffeine free every once in a while, for like a week or so, at minimum to reset my tolerance. I can see why someone would want to go without. You don't realize how it effects you until you don't have any. You'll have headaches for a few days, but the withdrawals aren't too bad.

It's a drug, like any other. You should try to understand how it effects you and your addiction/reliance on it. Sure, it isn't particularly dangerous, but I still think it's healthy to know how your body reacts. I think it's weird that people treat caffeine as if it isn't a drug, just because most people are addicted to it.