Philippa Perry said this quote

“ You may find that you have been telling yourself that practicing optimism is a risk, as though, somehow, a positive attitude will invite disaster and so if you practice optimism it may increase your feelings of vulnerability. The trick is to increase your tolerance for vulnerable feelings, rather than avoid them altogether.[…]Optimism does not mean continual happiness, glazed eyes and a fixed grin. When I talk about the desirability of optimism I do not mean that we should delude ourselves about reality. But practicing optimism does mean focusing more on the positive fall-out of an event than on the negative. … I am not advocating the kind of optimism that means you blow all your savings on a horse running at a hundred to one; I am talking about being optimistic enough to sow some seeds in the hope that some of them will germinate and grow into flowers. ”