If you caught the cover article in the NY Times magazine this weekend you were in for a real treat. Written by Emily Gould, she talks about obsessing with blogs, working for gawker, and then having the whole "blogger-celebrity-fame" ruin her life. This seems like a pretty easy train wreck to predict.
Think back to high school or college. When you had to study for a test, you didn't study 24/7 for months and months. It doesn't work. Why? You can't concentrate for that long, you lose focus, and most importantly the ratio of information retention to time is quite poor. That's why people cram (or at least study harder and more intense closer to the test). By learning more per minute you are more efficient and will earn a better grade.
Much is the same with work. Work all the time and you probably won't get much done. Work in a set period of time with set goals and you'll feel a pretty solid sense of accomplishment.
Imagine if you're a consultant and are paid by the hour. If you kept your clock running while you half-assed your work, I bet your clients wouldn't be real happy. Why treat clients better then yourself? You shouldn't. When you work for yourself, work hard, concentrate, and get the job done (think--deliver on the promise to yourself). When you work for your clients, work hard, concentrate, and get the job done (think--deliver on the promise for your customers).
Practice: Pick a goal, set a time period, and see if you can focus 100% (no e-mail, IM, TV) and get it done. Want help? Check out Journey Page operated by two friends Michael and Sheenah.