Coffee and Caffeine FAQ

How can someone who drinks 4 espressos a day classify themselves as a heavy user ? I've drunk that in my first Americano of the day. I may drink 6-8 of those in a day, i.e. 24-32 espressos a day. I think I've just scared myself as I haven't figured it out like this before - it also doesn't seem that much to me, one cup (i.e. 14 oz Americano) every couple of hours or so through the day. Maybe I should do something about my caffeine intake......