From the very beginning of a person’s life one learns that the purpose of life is not uninterrupted pleasure. Every infant suffers pains and illnesses. We should not perceive illness and pain as negative. Suffering teaches us humility. We learn that we do not have complete power over ourselves.
Once you are used to something, you feel some suffering if you lack it. Be very careful before making something a habit.
There is no such thing as a "self-made" man. We are made up of thousands of others. Everyone who has ever done a kind deed for us, or spoken one word of encouragement to us, has entered into the make-up of our character and of our thoughts, as well as our success.
The first real mental illumination I remember to have experienced was when I saw that the universe exists in each of its individual atoms - that is, the universe is the result of a few simple processes infinitely repeated. When a drop of water has been mathematically measured, every principle will have been used which would be called form in the measurement of the heavens. All life on the globe is sustained by digestion and assimilation; when by voluntary and traumatic action these stop death follows. The history of an individual mind is the history of the race. Know one thing in its properties and relations and you will know all things.
Human sorrow springs from three things: to want before it is due; to want more than your share; to want what belongs to others.
It is when we detect our own weaknesses that we come to pity or despise mankind. The human nature from which we then turn away is the human nature we have discovered in the depths of our own being. The evil is so well screened, the secret so universally kept, that in this case each individual is the dupe of all: however severely we may profess to judge other men, at bottom we think them better than ourselves. On this happy illusion much of our social life is grounded.
The best thing to give to your enemy is forgiveness; to an opponent, tolerance; to a friend, your heart; to your child, a good example; to a father, deference; to your mother, conduct that will make her proud of you; to yourself, respect; to all men, charity.