I'e abused coffee in the past as I'e felt like I had no choice or alternative. My tolerance for a little high now, and I'm a little addicted to it. I'e taken upward around 600 mg, and sometimes more but not very often (or much higher) I'e quit before but it's just hard to carve away enough time or get into a situation where it is more practical and easy. I realized a lot of the fatigue was lack of proper nutrients or diet, but still something I struggle with and have worked hard labour job the past and felt like I had to consume high doses to make it through and as well I was so overwhelmed during those periods. Is strong coffee verging on being a hard drug? I've heard and seen lot so other people do it, thus it felt like something sem-alright to indulge in, by got scared me, I have dark terrible circle sunder my eyes now from it lol. I knew mid aged guys who did trades work and drank a lot or either very strong coffee and they seemed relatively okay as well. Like filling the filter all the way to the top.