This is kind of a double negative, so I wasn't sure whether to show this or not! But it is somewhat true.
Perhaps it should read 'A Positive Mind will give you a Positive Life!'*
Anyway the point is... The more positive thinking that goes on in your head the more it'll show and the more positive you will feel. This will then rub off on other people and boom! Sending everyone your positive vibes and the earth will be a lot nicer to live in.
Kind of like the contagious smile!
Spread the positivity people!
*NB. The trick is to never counter-act your positive point with a negative one. So less of the never, no, can't and more of the yes, will, can! Hence why this quote probably is not the best. But at least I have corrected it & shared the knowledge. Non?!