Very interesting topic!
Why do I get high? Well, for one, it's fun. I love the experience of putting my mind on a whole different level. I love being with my friends and just being so fucking high, and being able to share that experience with them, whether the high was fun, emotional, sad, happy, hilarious, or a terrifying trip. Whatever it was, we were together, and our experiences getting high together have brought us closer together. I love that.
Also, as a Psych major, I simply find it fascinating how one little substance...or mixture of substances can alter your mind at such an intense level.
Lastly...and mostly, I get high for those cliche, bad reasons. I get high to feel the confidence I can't feel sober. I get high to forget about crap I don't want to think about. I get high because I'm bored. I get high to be happy, and have the optimism that some drugs tend to give me. And most of all, I get high to feel numb. When I'm high, I just feel so numbed to the things that have hurt me or that bother me in my life.