Speaking about the profound contradictions of human nature, Japanese actor Hiroyuki Sanada said:

"Some people dream of having a swimming pool at home, while those who have one barely use it. Those who have lost a loved one feel a deep sense of loss, while others often complain about family members still living. Those without a partner long to have one, while those who have one often don't appreciate it. The hungry would give anything for a meal, while the satisfied complain about the taste of their food. Those without a car dream of having one, while those who have a car always seek a better one."
The key to happiness is gratitude: truly seeing and valuing what we already have, and understanding that somewhere, someone would give everything for what we take for granted.