I've quit caffeine 5 or 6 times, dealt with the killer headache for a few days, and then felt really good not needing a daily fix.
The best part was that after abstaining for a while, an occasional large cup of coffee was like a miracle drug. What an intense energy boost! Like any addictive substance, caffeine becomes just a mild drug when used daily.
I'm back up to two tall cups per week, and a few Diet Cokes per day.
The Tuesday and Thursday coffees still pack the punch, but the daily couple 'o Diet Cokes have lost any powers they once had.
Time for me to ratchet down I guess before I find that even the $1 cardboard cups become as weak as the cans of cola.