He alone knows what he has done with life. In the privacy of his own home, he looks in the mirror and sees himself. And from head to toe, things are not good.
So he says, “I should teach others? I should provide guidance?!”
And we tell him, “Yes. Because that is your place upon this planet: We live in a time when all those who know Alef must teach Alef and those who know what comes after Alef must teach that too.”
“And G‑d Above, who formed you and put you in the here and now, He knows who you are and how you are and what you are capable of accomplishing. If He believes in you, you must as well.”