We are motivated by pleasure in life rather than pain. Many resolutions involve some kind of deprivation of pleasure whether it be eating, or stopping a bad habit. We know that although we enjoy our bad habits, their consequences are ultimately not beneficial for either our health or life. The desire for instant gratification for short term pleasure is far stronger than any mental logical sense of reason in most cases. We know in our head what we should do, but doing it when it opposes our immediate desires is tough.
Our mind is composed of two parts; the conscious and subconscious mind. Brain activity takes place through neurons. In one second of time the conscious mind uses two thousand neurons, and in that same second, the subconscious mind uses four billion neurons. This means that every second there are two thousand neurons making conscious decisions and four billion neurons making subconscious decisions. Which part of your mind has the greatest control do you think?