There are two sentences inscribed upon the Delphic oracle, hugely accommodated to the usages of man’s life: “Know thyself,” and “Nothing too much;” and upon these all other precepts depend.

Two things carry most of practical wisdom: an accurate view of yourself, and a sense of proportion. Knowing what you are actually like keeps you out of situations you would handle badly, and keeping things in measure stops the good ones turning into their own problem. Almost every other piece of advice is a special case of one or the other.

Test both this week. Ask someone honest what you are like to work with, and listen without defending. Then find the thing you have been doing to excess, even a good thing, and pull it back a notch.