For me, it is best to have both a short-term and long-term goal, all the time. For example, my short-term goal is to make it through Phase 1 succesfully, and my long-term goal is to lose 20 pounds/be a better runner. I love how so many people on this board have two tickers: a long-term goal ticker, and a short-term ticker.
For me, the problem with just a short-term goal is that it becomes to easy to say, "what will cheating matter in the long run?" However, if I have just a long-term goal, it seems so far off and unatainable that I get frustrated and give up.
Just my opinion