His older self had taught his younger self a language which the older self knew because the younger self, after being taught, grew up to be the older self and was, therefore, capable of teaching.

Take sex away from people. Make it forbidden, evil. Limit it to ritualistic breeding. Force it to back up into suppressed sadism. Then hand the people a scapegoat to hate. Let them kill a scapegoat occasionally for cathartic release. The mechanism is ages old. Tyrants used it centuries before the word "psychology" was ever invented. It works, too.

Most people who sneer at technology would starve to death if the engineering infrastructure were removed.

Humans hardly ever learn from the experience of others. They learn - when they do, which isn't often - on their own, the hard way.

Love is that condition in which the happiness of another person is essential to your own... Jealousy is a disease, love is a healthy condition. The immature mind often mistakes one for the other, or assumes that the greater the love, the greater the jealousy.

Men are more sentimental than women. It blurs their thinking.

People usually believe anything that they are told early and often.