What do you think of drinking at the age of 15?

I have nothing against it, but than again I'm not very much for it. A couple of weeks ago at a friend's birthday party my friends got drunk and I had some sips. It didn't affect me, I wasn't intending to get drunk. I noticed some adults around us giving us rude stares and whispering about us. It looked quite sad, as if we were trying to look carefree and nonchalant but it seemed as if were playing up to the stereotype of teenagers trying to look older than we actually are. What is your opinion of 15-year old kids and drinking? What do you think is the appropriate age to start?