People who prepare plans on how to reach their goals, which psychologists call "implementation intentions, " are more effective at reaching goals, by spelling out in their minds what they will do if an obstacle arises, says Peter Gollwitzer, a psychology professor at New York University.

WSJ: Resolutions: So Irresistible, So Hard to Keep

The intentions are there, but the execution and implementation are off.

FORBES: No More Goals! Make Promises Instead