I know exactly how you feel. I had my first LD a few days ago, and it sparked my interest in the topic again. When I realized I was lucid, I tried to flick my fingers to spark fire, but nothing happened. It's all about expectation really. If you TRULY expect something to happen, it will. But with me and you, we didn't fully believe we could do anything, as it was our first time at LD.

Aw, now I just disappointed myself by saying I could have firebended if I had wanted to...

BTW, read my lucid dream recollection as well, we basically do the exact same mistakes! Congrats on your LD though, I hope we both get more of these amazing personal virtual reality experiences!