Not overdoing it (to start with) is by far preferable tbh. My experience, for instance, is that inflamed achilles takes very long time (years) to go back to normal. To get it inflamed was fairly easy: resuming jogging a bit too swiftly after a winter break.

I know enough about people focusing too much on their wellbeing. You can trust me. Your mindset is more harmful than mine.

Sometimes the body needs rest, it's certainly true, but humans are adapted to a rather unforgiving environment in which you had to function even when in bad shape. Mind and body are connected.