When happiness is actually in possession, the thought of evil can no more acquire the feeling of reality than the thought of good can gain reality when melancholy rules. To the man actively happy, from whatever cause, evil simply cannot then and there be believed in.
William JamesThe stream of thought flows on; but most of its segments fall into the bottomless abyss of oblivion. Of some, no memory survives the instant of their passage. Of others, it is confined to a few moments, hours or days. Others, again, leave vestiges which are indestructible, and by means of which they may be recalled as long as life endures.
William James