it depends, different people do it for different reasons...

sounds like the original kid in this post doesn't have many friends and wants to get some attention. by acting like he's drunk or high he's trying to advertise that he's cool, that he likes to party, that if you're his friend you can feel like this to and have a good time. it all comes down to a cry for attention. maybe he doesn't have a great family life and is trying to compensate.