The second of Rabbi Yishmael’s 3 ways in which we disturb our own peace of mind:
2 — Dealing with the young:
In the Hebrew, “young” is indicated by the word תשחורת/tish’cho’ret. This word is based on שחר/sha’char/black, and is generally (although not universally) understood to refer to the “black hair” of younger people, as opposed to the “grey” hair of older ones. The verse then means: Be calm, or patient, with the young. Anyone who has dealt with children, lovable as they can be, knows the absolute value and necessity of remaining calm/patient with them.
“When you are with a person the color of whose hair is still black, that is to say, a young person…think of your own importance. Do not act frivolously or overly familiar with them…” 
Thematically, this follows the idea of being “easy” with those over us by telling us to be calm also with those over whom we might have power — i.e. our children, our students; even our employees.
On the other hand, of course, it doesn’t mean “be cold and unfeeling.” One must strike a balance between conveying warmth and maintaining being taken seriously in a leadership role. When I began working with children, I was fortunate to have an excellent, experienced supervisor. One of the first things he taught us was never to express disrespect for the child as a person when there was a need to correct a child’s behavior. His purpose was to teach us not to stir up needless defensiveness and anger on the child’s part.
But I learned over the years that expressions of anger towards children can have negative effects on the adult, as well. The anger we show reverberates in us emotionally and physiologically long after the incident itself is over. Few are able to maintain calm at all times simply by nature. For most of us, it’s a skill that we must learn over time.
I take “young” in another sense, too: We’re sometimes — perhaps often — confronted by behavior even in elders that could be called “immature.” Thus, I take this verse to imply: Be calm and patient with the immature behavior that you’re faced with in the course of daily life (aggressive driving is a good modern example).
“At such times, you should remain calm and aloof [or: detached], not lowering yourself to their level. Otherwise, you will be disrespected…” 
To do this, we can modify our own expectations of others in advance, as the Stoic philosopher Marcus Aurelius taught:
“Begin each day by telling yourself: Today I shall be meeting with interference, ingratitude, insolence, disloyalty, ill-will, and selfishness –- all of them due to the offenders’ ignorance of what is good or evil. But for my part I have long perceived the nature of good and its nobility, the nature of evil and its meanness, and also the nature of the culprit himself, who is my brother (not in the physical sense, but as a fellow creature similarly endowed with reason and a share of the divine); therefore none of those things can injure me, for nobody can implicate me in what is degrading. Neither can I be angry with my brother or fall foul of him; for he and I were born to work together, like a man’s two hands, feet or eyelids, or the upper and lower rows of his teeth. To obstruct each other is against Nature’s law –- and what is irritation or aversion but a form of obstruction.” 
Although Marcus Aurelius tells us to begin each day saying this to ourselves (mostly mentally), it might also be helpful to repeat it as often as necessary during the day; at the end of the day, too.
This, again, is very in keeping with Rabbi Yishmael’s advice.
 Maimonides, quoted in Goldin, Judah, trans. and ed.; The Living Talmud — The Wisdom of the Fathers; Mentor Books; © 1957 by Judah Goldin; p. 137
 Magriso, Rabbi Yitzhak b. Mosheh; “Ethics of the Talmud; Pirkei Avot (Me’am Lo’ez commentary);” Barocas, David N., trans. and Rabbi Aryeh Kaplan, ed.; Maznaim Publishing Company, © 1979; p. 150
 Marcus Aurelius; Meditations II:1