It is very true in a physical sense. "Use it" results in neural pathways being formed. What happens when you dont use them?

https://www.sciencedirect.com/science/article/abs/pii/S01602...

I meant in the physical sense of muscles/physical adaptations. I haven't read/written C++ in 10 years - it would take me a month to get back up to speed. If you never written C++ it would take you at least 6 months/year to get to the same level (depending on what we're comparing here).

Likewise for physical exercise - it took me a year to hit 100kg squat when I started getting into shape 10 years ago. I haven't been very physically active for years but I'd hit 100x5 in a month of starting gym again.