I'm 18 and I can say that none of those apply to me. I have never drank with friends or without my dad. My dad has offered me sips of whatever he's drinking ever since I was little - he doesn't think alcohol is bad, and neither do I. He taught us that if we were to drink, to never drink and drive, or get in the car with someone who has been drinking. But I just don't like the taste of the stuff - beer, margaritas, whiskey, etc. It's all butt-flavoured to me. :P But, even though I don't like the taste of it, I have drank sips of my dad's. Usually, everytime he's drinking something new, I'll have a sip. But never more than a sip of everything. Even on New Years Eve, he's poured a glass of champagne for me, I take one sip, go "icckkk", and give it away. He tries new stuff every year, and hasn't found one I like yet. :P
So I can't say I've never drank, but I can say that I will NEVER drink to get drunk, I will NEVER be drunk, and I have NOT had anything more than a sip at a time.