exactly it is perfectly said by you the mental laziness is the worst if a person is lazy mentally he or she will be lazy physically and sometimes some are lazy mentally but due to their mental laziness they will have to work harder that is why they said work smart not work hard.
if you are too lazy to think you will be enslaved by those that can think that is the principle of life and it is one of the things that is affecting most people in Africa laziness in thinking