You only need one disappointing experience to learn from it. Then this is something that I have been starting to understand as a human being and a psychology professional. However, it turns out, going through one event can completely change the way you see the entire world for the rest of your life. I know a lot of us can understand this in regards to violence or painful traumas, but, it entirely takes much less than a massively shocking event to change your behavior forever. For instance, it only took my brother one long, terrible morning as a HVAC specialist to forever change his yearly routine. On one of his first afternoons after working as a professional heating plus air conditioning worker for the local HVAC dealership, our brother was sent to some drastically difficult heating and cooling system repair works. He was already worried enough about demonstrating his recently earned heating and cooling certification for real residential heating and air conditioning buyers and then the heating plus air conditioning dispatcher sent him to the most difficult air conditioner and furnace repair works of the morning. My brother got stuck at each HVAC appointment for several hours longer than he expected. The next thing he knew, he had been working a 10-hour shift and his brain and body were in complete exhaustion mode. He was so tired when he left the last air conditioner repair service that he nearly fell asleep behind the wheel of the heating and air conditioning truck. To this morning, our brother is prepared for long, arduous HVAC repair services. He constantly keeps an extra mug of root beer and a handful of caffeine pills in his heating and cooling repair truck.