In modern pharmacology it's so clear that even if you have a fixed dose of a drug, the individuals respond very differently to one and the same dose.
“If it be true that our people represent a high percentage of mental vigor, the distinction is probably due, in some measure, to the extremely important part which Talmud studies have played in the spiritual life of the race.”
“I am an actor and I live in the world of pretend in my working capacity. I live in the world of my imagination.”