You are your way of thinking, if you think negatively, you will quickly grow old and die with the regret that you have lived an unhappy life. And on the contrary, you can be poor but always see positive things and enjoy the world around you. Will you then be unhappy with your life?
Another way is to be rich and think positively) Seriously, it's wonderful to be positive! Money can't buy happiness, but it's also important, and we need money to fulfill the needs and buy things we like!