People exercise for sport because we've automated away much of manual labour, so if you don't exercise, you look and feel like a string bean or a watermelon.

The AI age is trying to automate away our thinking, which runs the risk of making our brains look and feel like the same way as our bodies if we don't actively try to work them.

In the case of exercise, the majority of people don't pursue it in a somewhat post-labour era. I'm certain we'll see even less mental exercise in a post-thinking era. And it's deeply unsettling to think about how that will play out if we don't wake up and put a bit more mandatory/intentional thinking into the way we live with AI.