What does it mean to dream you can fly?

Lat night I had a dream that i could fly. I wasn't outside either, I was inside what looked like a big warehouse store with food I think. I started to fly everywhere and started seeing people I knew. I was showing off that I could fly to everyone inside. Doing some kinda weird moves in the air but I was happy. Why wasnt I outside flying? Why was I in a building? Why was I flying so happy even if I couldnt fy further up because there was a ceiling?