In my experience, caffeine tolerance is dependent on how much you regularly intake. I switched to decaf about a year ago (which still has a not-insignificant amount of caffeine in it) and I get the boost I normally would from a fully caffeinated cup once my body adjusted (a month or a so). I have to go out of my way to find good whole bean decaf but the taste is great, the effect is very similar, and the headaches I get on the weekend when I don’t drink any are far more mild. Highly recommend switching to exclusively decaf.