That means you adjusted back quickly, but it doesn't really answer the question. Which is: If you have coffee almost every day, does it still provide you an alertness boost?
I have been on and off coffee several times and my anecdote is that if you have coffee almost every day, it does provide you an alertness boost, but:
Your average alertness over the course of a day with coffee (when you're adjusted to it) and over a day without coffee (when you're adjusted to that) are about the same. The one with coffee just has more ups and downs. Without coffee it's more even. IMHO that evenness is a good thing.
Even at peak coffee, more coffee still stimulates my mind and makes me infinitely more focused. The only times coffee hasn't worked is when I'm genuinely sleep deprived, although I typically get 6-8 hours of sleep.