Thanks for sharing this. I'm also caffeine sensitive and unwittingly built up a tolerance as a teenager.
I realized the degree of my caffiene sensitivity when I had to give it up. Just quitting my one cup of coffee a day was rough. (The headaches!)
Now that I should be able to consume caffiene again, I can scarcely look at black tea without my heart racing. I really miss good coffee and it's effects, so I'm thinking about doing just this myself.
It's hard to start however, now that I know that I'm basically cultivating an addiction.
I am completely unfamiliar with what that implies or what access would actually be allowed, but I can see how that would raise concern.