long abandoned us and still they have a great, malignant, influence on our lives. This is the irony of the lack of trust. So, some of us prefer not to experience this sinking feeling: not to trust and not to be disappointed. This is both a fallacy and a folly. Trusting releases enormous amounts of mental energy, which could be better invested elsewhere. Naturally trust - like knives - can be dangerous to your health if used improperly. You have to know WHO to trust, you have to know HOW to trust and you have to know HOW to CONFIRM the existence of a functioning trust. First let me state clearly: people often disappoint and are not worthy of trust. They are often arbitrary, treacherous and vicious, or, worse, offhanded. You have to select your targets carefully. He who has the most common interests with you, who is investing in you for the long term, who is incapable of breaching trust ("a good person"), who doesn't have much to gain from betraying you - is not likely to mislead you. These people you can trust. You should not trust indiscriminately. No one is completely trustworthy in all areas of life. Most often our disappointments stem from our inability to separate one area of life from another. A person could be sexually loyal - but an utter danger when it comes to money (for instance, a gambler). Or a good, reliable father - but a womanizer. You can trust someone to carry out some types of activities - but not others, because they are more complicated, more boring, or do not appeal to his conscience. We should distinguish between people and allocate our trust accordingly. Then, we are not likely to be disappointed. We should not trust with reservations - this is the kind of "trust" that is common in business and among criminals and its source is rational. Game Theory in Mathematics deals with questions of calculated trust. We should trust wholeheartedly but know who to trust in which field. Then we will be rarely disappointed. As o...