I think there's some truth to this. Back when I was just about to replace my phone, the battery on the previous one would survive about 2 hours of screen usage,

I think there's some truth to this. Back when I was just about to replace my phone, the battery on the previous one would survive about 2 hours of screen usage, so I would start to measure aspects of my day to make sure I don't run out of battery and therefore lose all of the functionality that comes with having a working phone. I wouldn't go as far as to say that I would start using my battery as a unit of distance or time, but I definitely memorized the battery consumption of my evening commute more precisely than the distance.