"zhi zu" (satisfaction)

i like this song---"zhi zu" which sing by "ah sin"(wu yue tian), everytime when i happy or sad i will hear this song.. it seems like my medicine to cure my heart especially when i am in the low mood..
i like it very much. It is because the wording in that song. It is meningful to me also..
Sometime i think the things can make the ppl sad maybe they cannot feel "zhi zu". Everytime will ask for more...therefore if we cannot achieve it, then we well feel sad....