If you can't get enthusiastic about your work, it's time to get alarmed-something is wrong. Compete with yourself; set your teeth and dive into the job of breaking your own record. No one keeps up his or her enthusiasm automatically. Enthusiasm must be nourished with new actions, new aspirations, new efforts, new vision. It is your own fault if your enthusiasm is gone; you have failed to feed it. If you want to turn hours into minutes, renew your enthusiasm.
When we live habitually with the wicked, we become either their victim or their disciple; when we associate, with the virtuous men, we form ourselves in imitation of virtues, or at least some of their faults.
Ah! my dear Watson, there we come into those realms of conjecture, where the most logical mind may be at fault. Sherlock Holmes speaking with Dr. Watson.
Sir Arthur Conan Doyle (1859 - 1930)
Source: Sherlock Holmes and Dr. Watson in The Adventure of the Empty House