Percy Bysshe Shelley said this quote

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!