Heather

“Envy is itself a terrible obstacle to happiness. I think envy is immensely promoted by misfortunes in childhood. The child who finds a brother or sister preferred before himself acquires the habit of envy, and when he goes out into the world looks for injustices of which he is the victim, perceives them at once if they occur, and imagines them if they do not….Merely to realise the causes of one’s own envious feelings is to take a long step towards curing them. The habit of thinking in terms of comparisons is a fatal one. When anything pleasant occurs it should be enjoyed to the full, without stopping to think that it is not so pleasant as something else that may possibly be happening to someone else….With the wise man, what he has does not cease to be enjoyable because someone else has something else. Envy, in fact, is one form of a vice, partly moral, partly intellectual, which consists in seeing things never in themselves, but only in their relations….You cannot, therefore, get away from envy by means of success alone, for there will always be in history or legend some person even more successful than you are. You can get away from envy by enjoying the pleasures that come your way, by doing the work that you have to do, and by avoiding comparisons with those whom you imagine, perhaps quite falsely, to be more fortunate than yourself”
― Bertrand Russell

“If you don't love yourself, at least a little, if you don't create an armor of self-love and happiness around your heart, the feeble annoyances caused by others will become lethal and will destroy you.”
― Lewis Carroll, -Alice in Wonderland: The Complete Collection

“…another kind, by no means uncommon, in which one person sucks the vitality of the other, one receives what the other gives, but gives almost nothing in return. Some very vital people belong to this bloodsucking type. They extract the vitality from one victim after another, but while they prosper and grow interesting, those upon whom they live grow pale and dim and dull. Such people use others as means to their own ends and never consider them as ends in themselves.
Fundamentally they are not interested in those whom for the moment they think they love, they are interested only in the stimulus to their own activities, perhaps of a quite impersonal sort. Evidently this springs from some defect in their nature, but it is one not altogether easy either to diagnose or to cure. It is a characteristic frequently associated with great ambition and is rooted, I should say, in an unduly one-sided view of what makes human happiness.
Affection in the sense of a genuine reciprocal interest of two persons in each other, not solely as means to each other's good but rather as a combination having a common good, is one of the most important elements of real happiness, and the man whose ego is so enclosed within steel walls that this enlargement of it is impossible misses the best that life has to offer, however successful he may be in his career. Ambition which excludes affection from its purview is generally the result of some kind of anger or hatred against the human race, produced of it is impossible misses the best that life has to offer, however successful he may be in his career. Ambition which excludes affection from its purview is generally the result of some kind of anger or hatred against the human race, produced by unhappiness in youth, by injustices in later life, or by any of the causes which lead to persecution mania. A too powerful ego is a prison from which a man must escape if he is to enjoy the world to the full. A capacity for genuine affection is one of the marks of the man who has escaped his prison of self.”
― Bertrand Russell, The Conquest of Happiness

“Good and evil both increase at compound interest. That is why the little decisions you and I make every day are of such infinite importance. The smallest good act today is the capture of a strategic point from which, a few months later, you may be able to go on to victories you never dreamed of. An apparently trivial indulgence in lust or anger today is the loss of a ridge or railway line or bridgehead from which the enemy may launch an attack otherwise impossible.”
― C.S. Lewis, Mere Christianity