flatter oneself
feel assured；be sure of one's own talent or skill； be highly confident自信；敢说
I can flatter myself that my judgement is usually correct．我可以自信地说我的判断通常是正确的。
I flatter myself I can do it．我自信我能做。
She flatters herself that she is a better swimmer than he is．她确信她的游泳技术比他高明。