Well, I said "too quickly". You have to address tolerance for all drugs in this space, but some are ridiculous.
I couldn't even feel the Modafinil on day 3 without taking 5x the dose. That's a bit silly.
Instant release amphetamine ends up being more like a party drug for the same reason, though less extreme.
Compare that to a slow release amphetamine (prodrug) like Vyvanse where most people can hit a 2+ week cycle of constant use, or an indefinite cycle by only dosing a fraction of the week.
if you follow what other people do when using modafinil, they sometimes mix coffee w/ small amounts of modafinil which improves it's overall offectiveness. I personally prefer the mental zing of Loose Leaf Black Tea.