Happy Birthday and the Pirke Avot -the Wisdom of the Sages

At age 5, one studies Bible.
At ten, the Mishna.
At thirteen, one is responsible for the mitzvoth.
At fifteen, one studies Talmud.
At eighteen, one is ready for marriage.
At twenty, one begins a career.
At thirty, one is at the height of one's powers.
At forty, one achieves understanding [bina].
At fifty, one is prepared to give wise counsel [aitzah].
At sixty, one is given the deference of seniority.
At seventy, one is considered a sage.
Eighty is the age of heroic strength.