Of men and women: our feelings will never change. It's like a spring silkworm spitting all its silk before it dies, and it's like a burning candle burning itself to ashes before it dries its tears.
Of a career: devote yourself to a career, such as a silkworm wax torch, until you die without regret. Teachers and parents treat children.
Refers to determination: a firm belief, like a silkworm and a wax torch, will persist until death.