I have written on new year's resolutions before, once suggesting that we can resolve to change a behavior on any day. Whether our goals are related to health, education, work, communication, travel, philanthropy, or relationships, we need not wait until the clock strikes midnight on January 1. Nor should we get down on ourselves for "breaking" a resolution. Achieving a goal for the most part is better than not meeting it at all.
A key to life need not be to hit every mark we set, but each mark must evolve from our experiences. Cases in point: Muhammad Ali lost the Fight of the Century in 1971. In 1985, Apple's Steve Jobs lost his job in the company he created. Barack Obama suffered a landslide loss in a Democratic primary bid for Congress in 2000. In all three cases, these men came back to reach even greater heights.
Success is impossible without some sort of failure along the way. This truth tells us that achieving resolutions may have setbacks, but these failures should not define us. They should teach us, embolden us. So get to work on those writing resolutions, and work from the premise that failure is inevitable but instructive.