Wolfgang doesn't stare at them because that would be creepy, but they are, briefly, paying more attention to the kids than Michael. It's not that they idealise childhood — a good chunk of them are judgmental brats, and they can be cruel; Wolfgang has had to put up with a lot of them running up to touch them on a dare, exactly the way it had been when they were a kid — but maybe it's just that Wolfgang has never liked their peers, and now their peers are adults. Or maybe they just wish they could be more like that, totally un-self-conscious about the things they love.
When they realise they're being stared at, they start fidgeting again, frowning down at the sidewalk or at their shoes or something down there. “I like kids,” they mumble.