Never discriminate as to whom you study and whom you trust. Never trust anyone completely and study everyone, including friends and loved ones. - Robert Greene

Most people are perpetually locked in the present. Their decisions are overly influenced by the most immediate event; they easily become emotional and ascribe greater significance to a problem than it should have in reality.

Never pick a fight with someone you're not sure you can defeat.

People around you, constantly under the pull of their emotions, change their ideas by the day or by the hour, depending on their mood.

You must never assume that what people say or do in a particular moment is a statement of their permanent desires.