Training conditions you to act and react in certain ways. This conditioning becomes a way of life based on rules, principles, and systems developed to ensure your success. One of the most important Sandler conditioning principles is maintain a healthy self-esteem. You can’t be a champion—work effectively and enjoy long-term success—if you don’t feel good about yourself. Ironically, you fill your day with activities that have the potential to chip away at your self-esteem.