This is taken from the Jewish Talmud, the teachings of Rabbi Jehudah. It lists the different stages of life, and what men were ready for at each stage.
At 5 years: Reading Scripture
At 10 years: Learning the Mishnah (Jewish teaching)
At 13 years: Bound to the Commandments
At 15 years: Study of the Talmud (Jewish teaching)
At 18 years: The Bride Chamber
At 20 years: For pursuing a trade or business
At 30 years: Full vigour and authority
At 40 years: Maturity of reason, and discernment
At 50 years: For counsel
At 60 years: To be an elder, the commencement of agedness
At 70 years: For grey hairs
At 80 years: For special strength, or advanced old age
At 90 years: For a bowed back
At 100 years: As one that had already died and passed away, and ceased from the world
See: A. Edersheim. Sketches of Jewish Social Life (pages 100, 113)