Why would you wan to not understand?

If I ride my bike for an hour and my lower back hurts ... maybe I should ride for an hour every day?

If I do a half-hour light workout at the gym and afterwards my muscles are so ... maybe I should be doing that workout every day?

Pain can be a sign to stop .... or it can be a sign that some part of the body needs more work.

Pretty much all exercise hurts the first time. By your method, everybody should immediately stop exercising. By my method, everyone should continue exercising.

Which you choose is up to you.