We have vastly more control over our own happiness than the happiness of anyone else. If everyone focused on making themselves happy, the world would be a much happier place.

It's adapted from a John Irving quote. It shows that people should not sacrifice their own happiness just because it doesn't fit in.

The deliberate infliction of suffering on another person to achieve some end invariably corrupts that end. It is not reliable as a means of obtaining information, and when used as punishment for a transgression, reduces the torturer to the level of barbarity of the transgressor.