*Insert generic glass shattering noise here*
"RAINBOW!" Twilight hollered at Rainbow as pegasus crashed through yet another window.
"Huh?" Rainbow replied, brushing herself off. "By the way, Twi, I don't think that putting a force field around a hole in the wall would do anything good for you."
Twilight raised a brow. "Don't you mean glass?" she began, trudging away for a broom.
"Glass?" Rainbow asked in return, "What's that?"
Twilight frowned and pointed to a nearby glass vase.
"Cool!" Rainbow exclaimed, rushing towards the vase in question, "You made these flowers float by themselves?"
Twilight gave up on trying that day.