Pirkei Avot 2:6

"He used to say: A boor cannot be fearful of sin; an unlearned person cannot be scrupulously pious; the bashful person cannot learn, and the quick, impatient person cannot teach; anyone excessively occupied in business cannot become a scholar; and in a place where there are no leaders, strive to be a leader."

The previous mishnah, 2:5, deals with how to behave to others in the community, i.e., engage with the community, cultivate humility, do not be judgmental and communicate clearly.  Even the admonition to make time for study presumes that the reader is occupied in this world.  This mishnah, 2:6, explains the benefits of study, and then teaches the attitude that one must bring to it, and the actions that one must take for it to be effective. The first two verses teach that the study of Torah refines character; since a boor cannot be fearful of sin and an unlearned person cannot be scrupulously pious, learning gives the ability to be fearful of sin and to be pious, thereby improving our character.  But the next two verses admonish that study does not automatically guarantee learning: the bashful cannot learn and the impatient cannot teach.  Just as character is improved by learning, so certain character traits are necessary to learn and to teach (and in chevruta, teaching is a way of learning).  Finally, in the last two verses, Hillel calls us to action, as he often does at the end of his mishnayot.  We must carve out time from our occupations (which we learned in mishnah 2:2, are also meritorious) for study, and we must lead where others do not lead (from the context, this must be understood to refer to leading in study).  Taken together, the message is powerful: learning builds character, but to learn, we must subordinate our timidity and impatience to the value of learning, and we must make time to study and obtain a leader in our study, or in the absence of one, become one.