at thirty, one stands on one's own; turning thirty and becoming independent
A set phrase from the Analects of Confucius, used to express the idea that by age thirty a person should be established and self-reliant. Often quoted or referenced in discussions about maturity and life milestones.
The phrase 'at thirty, one stands on one's own' is a passage from the Analects.
He put 'at thirty, one stands on one's own' into practice and started his own company.
From the Analects of Confucius (論語), Book 2, Chapter 4: 子曰、吾十有五而志于学、三十而立、四十而不惑、五十而知天命、六十而耳順、七十而従心所欲不踰矩。 The phrase 三十にして立つ is a Japanese reading of 三十而立.