Yup, that stuff is great. I'm on Dexedrine, which is chemically similar, but feels quite different. For me, the focus that I get from Dexedrine is amazing, but no so much of a "high" comes from it. I don't mind this actually, because it means I have to seek out the most pleasurable things in life. My meds have done a lot for me as well. Before meds I was kind of in a slump. I had no drive to do anything with my life, but now I have picked up old hobbies again and pursued new ones like Philosophy and Physics. The reason for the high and the focus is because these drugs effectively create more dopamine in the brain. Dopamine is the neurotransmitter that makes you feel happy. It's often called the brain's reward mechanism. Your brain gives you dopamine every time you do something fulfilling.
Like loltex though I have lost quite a few pounds. It just seems like it doesn't matter how much I eat anymore, I still weigh too little. I have somewhat experienced the problem that you talk about. It's not so much of a logistical problem for me, it's more of a social problem. I am more inclined to work on whatever I am doing than humor those around me with fake sympathy. Going to High School is tough this way, because I am often dragged to mandatory events like assemblies or things of similar nature that are a waste of time. People get genuinely angry at me when they see me deep in thought and ignoring the speaker's story of how they ran a marathon, collapsed in a bush, and then came unto God. <<<< Joking. But really, people do get pissed when they feel like I am prioritizing something else over what they feel is important for me to hear. I have to be discrete with these things, especially during a classroom lecture that consists of reading and explaining self-explanatory directions that were given to us earlier. Never the less, I kind of like my somewhat blatant disrespect in this regard, and I enjoy having such clarity of thought on meds, and because of my interest in Philosophy, off meds as well.