Love and toothache have many cures, but none infallible, except possession and dispossession.
If better is possible, good is not enough
He's the best physician that knows the worthlessness of most medicines.
All highly competent people continually search for ways to keep learning, growing, and improving. They do that by asking WHY. After all, the person who knows HOW will always have a job, but the person who knows WHY will always be the boss.
Nor eye in a letter, nor hand in a purse, nor ear in the secret of another.
When in doubt, don't.