I woke up and ate a fatty breakfast and some mango. Hour later I ate half a brownie. 90 minutes later I'm the highest I've ever been. I couldn't do anything but stay in bed for the next 21 hours. So 1/4 or just a bite of the brownie would have been enough for me. I'm an occasional smoker (1-3 times a week).
I ate a half of one and it barely felt like anything, I had to dab 2-3 times afterwards just to supplement it. I'm not knocking his brownies, just speaking on what daily chronic tolerance will do to your ability to enjoy edibles properly.