We may not like it, but we know we need to feel pain. In fact, pain is used to protect our body from harm. It is a warning system. When our body feels pain it is as if to say: “Warning! Warning! … Stop what you are doing right now. Change it. Do something, anything, else.” For example, when your hand carelessly touches a hot stove, the sensation of pain will tell you to move your hand away. You will hesitate to touch the stove again. Pain is in fact protecting your body from harm or from more damage if you have already been hurt. Pain also helps to heal because the pain of the injury will tell your body when you need to have a good rest or when you are in danger of re-injury.

Buddha’s first lessons were the Doctrine of Suffering. He states, “Suffering is a necessary attribute of sentient existence.” A person whose life is driven by pleasure may have difficulty understanding this. We want to find a way to solve suffering because we feel suffering in our life. Experiencing suffering may make people lose their senses but it is also motivates people to pursue truth and find their own tremendous strength.
Mencius said,
“When Heaven is going to give a great responsibility to someone, it first makes his mind endure suffering. It makes his sinews and bones experience toil, and his body to suffer hunger. It inflicts him with poverty and knocks down everything he tries to build.
In this way Heaven stimulates his mind, stabilizes his temper and develops his weak points. People will always err, but it is only after making mistakes that they can correct themselves. Only when you have been mentally constricted can you become creative. It will show in your face and be heard in your voice, such that you will affect others. In your own state, if you don’t have legal specialists and impartial advisors, and outside your state, you don’t have enemy states to harass you, your own state will certainly fall to ruin. From this we can know that life is stimulated from adversity and anxiety, and death results from relaxation and pleasure.

Chasing joy or happiness and avoiding pain and suffering is a basic human instinct. But many people go out on a limb when they pursue external things hoping to bring joy into their life. Instead of lasting joy, in the end they fall into deeper suffering.
Take this story for example.
In a bar A asks B, “What was the happiest day of your life?”
B answers, “The day I took drugs for the first time.”
A asks B again, “What was the most painful day of your life?”
B said to A, “The day after I took drugs for the first time.”