I overheard this conversation between my Mac and an old laptop of mine:
"Hello, I'm a Mac."
"And I'm a PC."
"I haven't bothered to upgrade from OSX 10.3.9 to 10.4, so most new software doesn't work."
"Too bad, Mac. I'm still running Windows 2000, and I've never had any problems with installing new software."
"I can't even open some disk image files because they were created with OSX 10.4."
"You know, Mac, Microsoft go out of their way to make sure software is compatible between Windows versions, to the point where the operating system is so bloated and full of patches that it hardly runs at all."
"Well, Macs don't care much for backward compatibility and we force our users to upgrade to every new little release of the operating system. We even switched our CPU architecture twice."
"Hell, I'm still running on hardware that is backwards compatible with an 8 bit processor from 1978."
"Yeah? Well, actually, PC -- I'm doing that too."
At this point, the PC's wireless PCMCIA card stopped working and the conversation came to an abrupt end.