My ex and I have two grown sons who both experimented with drugs.
The oldest smoked pot a few times after he got out of high school and of course had a fake id for years before he turned 2l. He didn't like pot, it made him sleepy and he was born sleepy, so it was a lousy combination and he didn't see what the big deal was. Alcohol, now that he's over 21, he can take or leave, no biggie one way or another to him. That and it costs too much money as far as he's concerned and he'd rather not waste is money on something he can't hold on to.
The youngest son, he smoked pot a little in high school, until a teacher nailed him and he joined the Army on early whatever it's called, during his senior year. Uncle Sams had him for a few years now, so drug wise according to what he says he's clean. Alcohol for him, now that's a whole 'nother story. It's his life and he's going to have to live it, not me.
As for having been in the Seed and thinking we'd know it, if it happened, both the ex and I missed the boat altogether. We didn't have a clue. We always had what everyone called "good boys", no badittitudes other than the typical teenage hormonal rush and typical teenage attitudes towards their parents, not a thing to give away what they were doing or what they were up to. Both of them ended up telling me later on, cause they both felt guilty - they're words - not mine.
Do I wish they hadn't tried drugs, yea, does it upset me that they did, no. They are "good boys". They are on their own, living their lives as they see fit, just the way they're supposed to. Our kids, just like everyone elses kids, will do what they will do, just as we did what we did. It's the course and nature of life. Some turn out better than others regardless of what we do or try, how we raised them and sometimes in spite of us and how we raised them. It's life.