你的心情取决于你如何看待这个世界。如果你觉得这个世界充满欢乐，那你会变得快乐；如果你觉得这个世界充满悲伤，你会感到悲伤。就是这么简单。

You are how you see this world. If you see it as a happy one, you'll be happy. If you see it as a sad one, you'll be sad. It's as simple as that.