Senses
若要人不知，除非己莫为/ 若要人不知，除非己莫為 if you don't want anyone to know, don't do it
(proverb) The only way to keep a secret is not to do the deed; if you do something wrong, people will inevitably find out about it.
若要人不知，除非己莫为/ 若要人不知，除非己莫為 if you do not want others to know, do not do it yourself
the only way to keep a secret is to not do the deed in the first place; wrongdoing will eventually come to light