Earlier this year I threw my son his USB earbuds container. Not a heavy thing. I threw it in a high arc, and on its way down it glanced off the edge of his MacBook screen. It seemed like the lightest of touches, but it must have hit in just the right (or wrong) spot, and the screen ended up with a large crack, and stopped working. I was super surprised how fragile the screen was, especially given how tough iPads and iPhone seem to be. When it happened, I couldn't believe such a light glancing blow could have done it. I was definitely responsible for cracking the screen through my actions, but it did highlight to me that macbooks are not robust at all, not the high quality I had come to expect.