There are many things to learn. But it may not be possible to attend classes or to find gurus to learn what all one desires. One can learn through studying books or by listening to elders, discussing with the scholars, and the like.
Once a man took his son to a sage and told the sage, ‘This is my son. He does not listen to me. I tell him not to eat too much sweet candy.
Teaching is a sacred profession. The teacher should dedicate himself to the teaching profession. The teacher should remember this every time he teaches.