My First Intentional Lucid Dream!

Okay, so I have been having lucid dreams ever since I was really young, but they weren't intentional and I kept waking up. But last night I really had an awesome, vivid dream. The lucidity lasted for about 20 - 30 minutes so I am very happy!
Okay, so the dream started with my school and my friends in a class. I accepted that this was reality so the dream kept on rollin'. After about an hour, I had a false awakening in my own bed. I also quickly wrote in my dream journal! Then after that, somehow I realized I was dreaming, (Don't ask me how :P) and the dream scene changed from my room to my school. I quickly told myself to calm down and not panic. Afterwards, I tested out telekinesis on a book and it worked like a charm! I was so damn happy! So I quickly went to my Dream Friends and told them what I could do. And it turned out that one of my friends had the power to shoot a highly concentrated laser out of his chest. So I tried that and succeeded. I also tried to shoot out a cold ion beam from my hands and I succeeded at that too :D
So, after getting comfortable, I decided to go to the school gym and levitate a dumbbell and throw it at this girl I hated. Only I couldn't really throw it at her, so it hit her toe instead :P Then the girl screamed out in agony. I laughed a little and she must have seen me and realized that I was the one who hurt her toe. So the girl started running towards me and I dodged. I tried to levitate her or at least push her but my powers wouldn't activate!
The dream ended after that... Anyone have any ideas as to why my powers wouldn't work?

Sounds like a great lucid, congrats! i guess after your failed attempt at throwing the dumbbell you doubted your abilities. Reality check to maintain lucidity next time.