By Alison Osius, Special to The Denver Post Long ago, I used to take two little boys to our town library. Poking around among the stacks, I’d turn to show them something, and see … empty air. I’d peer around, then hear shouts through the door. They’d crept away and were whizzing by on their scooters. My mother always brought us home bags of books from the local library, especially in summer, or she’d take us along to choose our own.