I upgraded my Macbook from Snow Leopard to Lion, then gave it to the girlfriend. She'd never used a Mac before. She didn't even notice that the scrolling was the opposite way round to other devices. Not until I pointed it out to her after she'd been using it for a while.

I now use a Lenovo Thinkpad T420 with Ubuntu instead. It's come a hell of a long way over the past few years.