All truth in the long run is only common sense clarified.
When we believe ourselves in possession of the only truth we are likely to be indifferent to common everyday truths.
There is never vulgarity in a whole truth however commonplace. It may be unimportant or painful. It cannot be vulgar. Vulgarity is only in concealment of truth or in affectation.
Above all I would teach him to tell the truth Truth-telling I have found is the key to responsible citizenship. The thousands of criminals I have seen in 40 years of law enforcement have had one thing in common: Every single one was a liar.
Friendless. Having no favors to bestow. Destitute of fortune. Addicted to utterance of truth and common sense.
Work hard use your common sense and don't be afraid to trust your instincts.
If we put our trust in the common sense of common men and 'with malice toward none and charity for all' go forward on the great adventure of making political economic and social democracy a practical reality we shall not fail.
It is essential to employ trust and reward those whose perspective ability and judgment are radically different from yours. It is also rare for it requires uncommon humility tolerance and wisdom.
If you travel around America you see different sections of highways donated by this or that person and that's a slow beginning of what may end up being a situation common in the Third World: some sections of highways in wealthy areas are beautifully maintained and other parts are just dirt-strewn potholes.
By the time I'm 40 interplanetary travel will be common. Nobody will want to talk to me at that age anyway.