Achaaryaath paadam aadatthe paadam sishya swamedhayaa paadam sa brahmachaaribhya sesham kaala kramena cha

This is a significant saying found in the Hindu scriptures, called Smruthies.
What does it imply? It implies that a person can get only one quarter of knowledge from the Achaarya (the teacher), another quarter by analyzing self, one quarter by discussing with others, and the last quarter during the process of living by method addition, deletion, correction, and modification of what is already known to him.

It is not the critic that counts; not the man who points out how the strong man tumbles, or where the doer of deeds could have done them better.
The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deeds, who knows great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows in the end the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who neither know victory nor defeat.

- Theodore Roosevelt