Quote from : The Phantom Tollbooth Book

Would it be possible for me to see something from up there?" asked Milo politely. "You could," said Alec, "but only if you try very hard to look at things as an adult does." Milo tried as hard as he could, and, as he did, his feet floated slowly off the ground until he was standing in the air next to Alex Bings. He looked around very quickly and, an instant later, crashed back down to the earth again. "Interesting, wasn't it?" asked Alex. "Yes, it was," agreed Milo, rubbing his head and dusting himself off, "but I think I'll continue to see things as a child. It's not so far to fall.