I think if would like to be positive thinking person have to practice . when have to met bad situations ,We can choose how to think in negative or positive way. The point is when u are thinking, u have to know yourself that u are thinking in negative and it can make yourself feel down . When u know u think in negative way so u just let bad thinking go away and come back to focus in the present .focus your breathing . It can help to stop thinking . And meditation also can help you to clear your mind and be positive . Sometimes situations will change ,only u change your mind . Every situations have two side. We can choose to think in the way that make u happy .