" We rest; a dream has power to poison sleep.
We rise; one wand'ring thought pollutes the day.
We feel, conceive, or reason; laugh or weep,
Embrace fond woe, or cast our cares away;
It is the same: for, be it joy or sorrow,
The path of its departure still is free.
Man's yesterday may ne'er be like his morrow;
Nought may endure but Mutability! "

― Percy Bysshe Shelley , The Complete Poems