bike maintenance - cables

Some guy told another cyclist who told me she had heard that cables sometimes break.

Maybe.

Cables do slowly stretch.

The stretching mostly happens soon after installation and it’s usual to adjust them at that stage. Say after 100km.

But carry a spare brake and gear cable just in case. They are cheap and light.

They may well be unobtainable out in the middle of nowhere if for some unlucky reason you need one.