I did the same, but never got the same feeling as the first time I took Modafinil. First time was great. Second time was good. By the fourth of fifth time it was only okay.
I had similar experiences, effect was much weaker after 4-5 days but I think it was better for work. Initial 3-4 days were very similar to taking cocaine, I was too high to do good work.
Well, I have that first-time experience with adderall and modafinil if I've given myself a break from it. Medication "holidays" (periods of abstention) are pretty much standard practice for stimulant meds like adderall to avoid tolerance/dosage creep and anecdotally this is true for modafinil in my experience as well.
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.