It isn't what y

It isn't what you have or who you are or where you are or what you are doing that makes you happy or unhappy. It is what you think about it.
讓你快樂或不快樂的，不是你擁有什麼、你是誰、你在哪裏或你在做什麼，而是你對此怎麼想。    ------卡耐基