GM sir, a quick thought:

- The industrial revolution replaced muscle labor and suddenly tractors, cars and machines are making most of muscle. So, what does the human with all that energy? Inactivity thought the gym. So, muscles are now something for people who want to take care, self-care, ya know?
- The information revolution that we're living now is about artificial intelligence and suddenly, people are not making too much effort in autonomous tasks. So, what's the activity equivalent to gym but for our thoughts? Books. Not videos or movies, just books because, it makes our brains do something like cardio.

Have a nice day sir.