Why does Maniac decide to not live in the band shell any longer?

Maniac is always moving around from place to place. It's no wonder that one of his greatest desires is to find a place that he can call home. After losing not one but two families, Maniac winds up sleeping in the buffalo enclosure at the zoo. An old man called Grayson, who works at the park, cleans him up, gives him some clothes and something to eat, and takes Maniac to a baseball equipment room behind the band shell.
Maniac and Grayson soon establish a strong bond; Grayson becomes almost like a father to the young man. But sadly, it's not destined to last. If there's one thing you can pretty much guarantee with Maniac Magee it's that he never gets a chance to put down roots for very long. And so it proves once more as Grayson passes away one Christmas, leaving Maniac all alone. Life in the equipment room just won't be the same without Grayson, so Maniac leaves his latest short-term abode and goes back to stay with the Beales.