The English translation for “快乐源于自己的内心” is “Happiness comes from within.” This phrase emphasizes the idea that true happiness is not来自外部因素， but rather from the inside. It suggests that the things we value and enjoy are not external to us, but rather things that are deeply within us and affect our emotions and thoughts.
In English, the phrase can be translated as “Happiness comes from within” or “快乐源于内心.”