If we were using coffee as currency wouldn’t there be an upper limit? Like if someone gave me 3 coffees I’d be good for the day, but 10 and I’d either be too w

If we were using coffee as currency wouldn’t there be an upper limit? Like if someone gave me 3 coffees I’d be good for the day, but 10 and I’d either be too wired to cut your hair well or drink 3 and watch the other 7 get cold and stale.