A wise person is not bored in their solitude; they are bored in a crowd of fools. Source: Internet
A wise person can always correct their mistakes, while a foolish one usually cannot even admit them. Source: Internet
When a wise person gets angry, he sits down and remains silent to calm his heart, so that anger does not take over him-allowing him to remain the master of himself. Nectarios of Aegina
The wise person is only cheated once. Finnish Proverb
A wise person sometimes changes his mind, but a fool never does. Italian Proverb
The friend of a fool is a fool. The friend of a wise person is another wise person. The Husia Proverb