I once had a desktop computer that had great uptime, but started to consistently crash when I got up and left the room to get a drink of water.

Turns out it was old building with loose floorboards. The vibrational force of standing up was enough to short out a failing power supply. As long as I sat my desk, it was fine.

But I had a co-worker who had a worse problem with getting up to get a drink of water. Once while she was kitchen, an eight foot steel lighting ballast came loose from the ceiling and felt right onto her chair.That what-if memory still haunts me.