I wonder that too. My handful tripped in my front yard yesterday, got the slightest scrape imaginable, didn't even bleed, and he was hollering like I was murdering him. I tried to calm him down, but he was waaaay past the point of no return. I didn't want the rest to have to come inside, so he was put on my front step to wail away. Every time a neighbour walked by I'd announce loudly "you're fine buddy, you only tripped, there's no need for a meltdown," or something like it, just so they wouldn't think he was actually hurt. If only he'd realize he's missing out on outside time for ridiculous reasons!