How did anyone ever figure out that if you take a random plant and harvest it just right, dry it, and smoke it you will reap its glorious effect, or that if you take another random plant, pick its berries, pull out their seeds, roast said seeds, and steep them in water you will reap its glorious effects? Out of the billions of plants in the world how did they find out that these plants have clandestine properties that can be coaxed out?