Well, over human history, I imagine it was quite the trial and error process to discover some form of alcohol, and to tweak and refine it to various, drinkable forms. Sounds like quite the arduous process, and one you'd have to be highly motivated to go through. I think the same can be said for cigarettes, caffeine, and various chemical "jackpots" in terms of that motive I think is behind all of the above: pleasure seeking. I think our species is highly driven to achieve and experience pleasure, especially in such an immediately gratifying form as a recreational (or habitual) drug. I think nature knew this well enough to guarantee the survival of our species by making procreation so intensely pleasurable. It seems to me that we are "hard-wired" to seek pleasure. So, if alcohol had never been discovered, I am sure we'd have found a way to a similar substitute, perhaps having the results of increased consumption of the other leisure chemical indulgences. I wonder...what if we were not driven by and to pleasure? Would we as sentient beings be satisfied by the wholesome joys? Would we have been so unmotivated as a species that natural selection would have extinguished us as soon as sustaining our individual biological survival would have slowly driven our ancestors to an irresistible and inevitable inertia - with fatal results, that is, extinction?