Many folks are indeed caffeine-intolerant....and even more, like myself, are probably mildly addicted to it. Withdrawal from caffeine is not dreadful (usually mild headaches for a while), and coffee will not be declared a dangerous drug anytime soon. I cannot drink it at night (if I want to sleep), but I do have a nice cup of strong coffee each morning. Surprisingly, good coffee bean is easier to find in California than here in Creuse. The Ecomarché in Felletin does sell whole beans of very acceptable quality, in a nice big gold bag. I prefer to grind whole beans daily.
For a discussion of the benefits and risks of caffeine, you can look in this
We do also keep a big supply of herbal teas, widely sold in France, for evening use, and to offer guests. And since the San Francisco area has a huge Asian (and hippie) population, we bring a number of more exotic teas with us.