Nine-tenths of wisdom is ...

Nine-tenths of wisdom is being wise in time.
Nine-tenths of wisdom is being wise in time.

More phrases

If one does not know to which port one is sailing, no wind is favorable.
What a distressing contrast there is between the radiant intelligence of the child and the feeble mentality of the average adult.
We are masters of the unsaid words, but slaves of those we let slip out.
I have always found that mercy bears richer fruits than strict justice.
A lie gets halfway around the world before the truth has a chance to get its pants on.

Quotes from the same author

Keep your eyes on the stars and your feet on the ground.
“I care not what others think of what I do, but I care very much about what I think of what I do! That is character!”
“We must dare to be great; and we must realize that greatness is the fruit of toil and sacrifice and high courage.”
The mother is the one supreme asset of national life; she is more important by far than the successful statesman, or business man, or artist, or scientist.
When she (my mother) passed away, I kind of understood the commitment that she made to make sure that I could stay in skating. And I wanted to live up to whatever I could. Not so much win everything, but just to be the best that I could possibly be, to honor her memory and everything she went through to make sure that I was given the opportunities to be the best that I can be. Not to be a world champion or an Olympic gold medalist, but to be the best that I could be. And that was the most important thing that ever happened in my career.