People think that they want me, but I am horrible when I show up. The person I attack cannot be pleased nor can he escape me though he should travel over continents and between planets. I afflict inwardly the weak, the foolish, and trouble the physcially active who lack wisdom. I push many to action, though I be evil myself. I work best like a warm, bloody, sheep-skin draped over a cow that will not rise by an olde-tyme farmer. My evil brother is sloth. The Romans called by noble thing I may be transformed into otium. What am I?