始 - Shi3 - Begin

For anybody who happens to be starting their seventieth year today, there is a Chinese proverb:

人生七十才開始 - Ren2 Sheng1 Qi1 Shi2 Cai2 Kai3 Shi3 - Person Life Seventy Just Starts — A Man’s Life Begins At Seventy

(Life also begins many other times, according to Google.)