I just made the discovery in 2006 and everything else just unfolded all by itself.
Bottom line square one appears to me to be that we were once just like all of the other species before we began ingesting stimulant drugs.
No doubt accidentally at first and then deliberately as our desires and addictions grew and our stimulated inventiveness kicked in and we learned how to grow and process these carbohydrates and sugars and starches and make alcohol and caffeine.
Nicotine and cocaine in the Americas to go with this.
They chewed limes and coca leaves in the Andes Mountain Region I believe to get high on Cocaine.
Seed from Coca plants for caffeine the Aztecs and Maya.
Highbred corn and highbred potatoes.