Back in your grandfather's day there was weed very similar to the kind you can buy in your dispensary...it was just kind of rare. Two famous types in the late 60s-early 70's were Panama Red and Acapulco Gold. I remember scoring some "Gold", smoking some with my friend and having a nearly psychedelic experience. The main difference was, as you hint, in the growing and harvesting. A lot of weed back then was just the whole plant, flowers, leaves, stems, obviously lower in strength. Illicit growers as early as the '90s got scientific about growing and the quality just rocketed, but unless you knew the grower the provenance was always in question. I love the idea of legal and aboveboard pot, the possibility of eliminating all possible adulterants.