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The fountain of content must spring up in the mind, and they who have so little knowledge of human nature as to seek happiness by changing anything but their own dispositions will waste their lives in fruitless efforts.

暴政終將崩潰，自由永存。

Vision without execution is just a dream.

希望不是一種感覺；它是一種可行的事情。

Persistence is key in mathematical research; many great results come from long struggles.