Wisdom is not wisdom when it is derived from books alone.
Mingle some brief folly with your wisdom.
Sad people dislike the happy, and the happy the sad; the quick thinking the sedate, and the careless the busy and industrious.
Whatever your advice make it brief.
It is no great art to say something briefly when, like Tacitus, one has something to say; when one has nothing to say, however, and none the less writes a whole book and makes truth into a liar - that I call an achievement.