Of all the things I’ve taught, the Three Gates pops up most often on other people’s threads. Of all the things that have created joy, success, and happiness in the lives of the masters, the interaction of Body, Heart, and Head have been most instructional. Three Gates, Three Centers.
Start with the assumption that all animals seek to avoid pain and gain pleasure, such that the meaning of life is to seek joy. The less evolved version of this would be “to avoid pain.”