At five years of age, the study of Scripture; at ten, the study of mishnah; at thirteen, the obligation to observe the mitzvos; at fifteen, the study of Gemara; at eighteen, marriage; at twenty, begins the pursuit [of a livelihood].

Ethics of the Fathers, 5:22

            

In other words, for the first twenty years of life, a person focuses almost exclusively on his individual growth: the acquisition of knowledge and wisdom and his moral and spiritual development. The age of twenty marks the point at which he ventures out to the world and begins to concern himself with the material involvements of life.

This is why the Torah considers the age of twenty such an important milestone in a person's life. In commanding Moses to take a census of the Jewish people, the Almighty directs: "Count the heads of all the congregation of the children of Israel... from the age of twenty and upward, all who are fit to serve in the army of Israel, you shall count them."

One who engages only in the spiritual enrichment of his own self cannot count himself as a member of the "army of Israel." While a period of intense self-development is crucial to a person's fulfillment of his mission in life, and while a person must continue to set aside inviolable "islands in time" devoted to the nurture and growth of his spiritual self, these must never be seen as an end in itself. The purpose of the "pre-twenty" times and aspects of a person's life is for the sake of the "pursuit" that must follow: that he apply his personal attainments to develop and sanctify the material world "out there."

Enough!

A similar sentiment is expressed by the Torah in the opening chapter of Deuteronomy. Here, Moses reminds the Jewish people, "The L‑rd our G‑d spoke to us at Horeb, saying: `Enough have you dwelt at this mountain! Turn away and travel on....'"

The mountain in question is Mount Sinai, scene of the most monumental event in human history: G‑d's communication of His wisdom and will to man.

But the enlightenment and perfection of one's own mind and character is a prerequisite to life, not its aim and end. One must view his own attainments as the tools by which to enlighten his fellows and perfect his environment.

No sooner had the people of Israel experienced and absorbed the greatest Divine revelation of all times, than they were virtually driven away from the mountain. "Enough!" they were told, enough of your basking in your newly gained insight and spirituality. Turn away, travel on, there is a world out that has much to receive from you....