I grew up in a pretty permissive household too, there are photos somewhere of me as a toddler sucking on dad's beer bottle (I blame him for my taste for "Blue") and I have distinct memories of the taste of dad's Scotch... and when I was a teenager my mom lent me $20 knowing full well it was going up in smoke. She asked, "Is this for marijuana??" and I giggled a lot without answering because I can't lie to my mom, but she lent me the money anyway... alas, I can't smoke pot anymore either, last time I tried, it did a real number on my lungs and caused an anxiety attack... not pleasant.
My first full-on drunk was at a family wedding when I was 16, it was an event involving Europeans, where if you're old enough to ask for it, you're old enough to drink it. But I do have to be careful how I drink, I think I'm like my dad was in that, I have to set my limits while sober, because once I get started, I won't stop till I hit the floor. The 3-drink maximum (or 5 shot max depemding on what I'm drinking) has kept me from being the "designated drunk" fairly well, and now that I'm in the habit, it's not a problem, especially now that my alcohol tolerance often exceeds my hangover tolerance anyway.
And I do know of households where the parents were so adamant about not doing things till a certain age that the kids either did it behind the parent's backs and did it stupid and got hurt, or went completely off the deep end when they were finally permitted, and got hurt... but as my brother and I so clearly illustrate, what works on one kid may be the worst possible way to treat another...
If I have a minor over (it's happened, one of my gaming friends was 16 when we met and the rest of us are in our 30's) and we break out the booze, a phone call goes out to their parents and we ask if we can serve them alcohol. If the answer is no, we respect that and don't rub it in.
And if my nephews happened to be over while I was getting a batch started, I'd ask my brother if they could help or if they should stay in the other room till I'm done... it's not like they would be exposed to alcohol, after all, but I respect his "dry" household to whatever extent he deems necessary.
