Thirty days later, you'd felt nothing. No lift, no focus, no reason it was any different from the plain coffee you gave up to drink it.
You're not imagining it, and you're not gullible. I know, because I did the exact same thing.
I'm not a doctor or a nutritionist. I'm someone who ended up with a shelf of half-finished bags I couldn't stand to drink, got sick of feeling nothing, and set out to find whether the whole category was a con. So I read thousands of reviews, bought the five trendiest brands, and drank every one.