What is the meaning of [A man too busy to take care of his health is like a mechanic too busy to take care of his tools]

“We gotta make a change, It’s time for us as a people to start makin’ some changes, Let’s change the way we eat, Let’s change the way we live, And let’s change the way we treat each other, You see the old way wasn’t workin’,So it’s on us to do what we gotta do to survive”