Approximately 90% of adults consume caffeine daily to block adenosine receptors and feel 'normal'.

“Nowadays, we certainly live in a time in which we use-- in fact, 90% or more of adults and half or more of adolescents and teenagers use caffeine as a way to negotiate with, to borrow against this natural pattern of adenosine making us sleepy.”

“So if 90% of the adult population of the planet Earth is consuming caffeine every day, that means 90% of the adult population of planet Earth is blocking their adenosine receptors for some portion of their daily life, and then their adenosine is binding to the vacant receptor once the caffeine has dislodged. And why are 90% of adult humans consuming caffeine every day? Well, to feel more energized, more focused, to have more both cognitive energy and physical energy. Now, of course, most people are not walking around thinking, oh, caffeine gives me more energy more focus, et cetera. Most people are consuming caffeine every single day and are consuming caffeine every single day in order to feel, quote, unquote, normal, to be at their baseline level of cognitive ability, and physical energy, and so on.”

“The current estimates are that 90%-- that's right, 9-0, 90%-- of adults throughout the world consume a caffeinated beverage every single day. That's a staggeringly high number, making caffeine the most popular drug on the planet.”