How many times have you known that you should do something but have failed to do it because you're not in the mood? Like going to the gym. Skipping dessert. Calling your grandmother. Apologizing to someone you've inadvertently offended. You know that you should but you just don't feel like it.
The ability to override your feelings and make choices that are wiser is a very important determinant of success. There is a classic experiment relating to this in the field of child development: in a series of studies that began in the late 1960s and continue today, psychologist Walter Mischel, PhD, found that children who, as 4-year-olds, could resist downing a marshmallow placed in front of them, and instead hold out for a larger reward in the very near future (two marshmallows half an hour later), became adults who were more likely to finish college and earn higher incomes, and were less likely to become overweight.
If you are someone who tends to be ruled more by emotion than by logic you can wind up self-sabotaging quite a bit. It's likely that when you encounter a situation in which you know you should do something but "just don't feel like it," or when you find yourself knowing that you shouldn't do something but find it easier to just go ahead and do it anyway, you can benefit from some training in self control.
There are two fundamentally different, and often warring, parts of the "thinking" brain: an "urgent" part demanding immediate gratification (the limbic system), and a cooler, goal-oriented part (the prefrontal cortex). The secret of self-control is to train the logic-driven prefrontal cortex to kick in sooner rather than later, offering a different outcome than does the more primitive, emotionally driven limbic system*.
There are a number of ways to train yourself along these lines. Devise specific if-then commitments to yourself, like “If it’s before noon, I won’t check email” or “If I feel angry, I will count backward from 10” or "If I don't feel like doing something I will write down three reasons supporting why I shouldn't. Don't just think these commitments, say them out loud, preferably to another but if necessary only to yourself (speaking ideas gives them additional strength). If done repeatedly, you may get your brain to at least consider your options. Other examples: Don’t eye the basket of bread; just have it taken off the table. In moments of emotional distress, imagine that you’re viewing yourself from outside, or consider what you might tell someone else to do in your place. When a waiter comes by with a dessert cart, imagine that a cockroach has just crawled across it. The point isn’t to eschew desserts forever, rather it’s to effectively marshall self-control when you want it, and be more disciplined in carrying out long-term plans.
Affirmations can be an effective way to change behavior for many people. Affirmations relating to improving self control could include such statements as: "I have the power to choose my reactions to things;" "Day by day my ability to control my thoughts and feelings is increasing;" "Increasing my self control will lead to increasing my success."
Regular physical activity, healthy eating, and adequate sleep have all been shown to improve one's ability to self control. Evidence for this comes from numerous studies that show that people who are hungry or tired invariably make emotion rather than logic-based decisions. People who are angry or lonely also fall into this category, hence the warning acronym HALT (Hungry, Angry, Lonely, Tired) suggesting great care in making decisions from any of those 4 emotion-based places.
Looking back at the way your emotions impacted important decisions in the past can be valuable. Have you made emotion-based decisions that you've regretted? What different decision would you have made if operating from the logical side of your brain?
A final technique that is effective for many is a regular meditation practice. Not meditation that attempts to "empty the mind" (virtually impossible for most people), but mediation that focuses on observing the thoughts that pop up in our minds quite randomly and then refocuses attention on a constant "home base" like a candle's flame, a mantra, or (most effectively in my view) the very subtle feeling of air moving into and out of our nostrils as we breathe through the nose.
Remember that emotions are inherently unstable and can shift rapidly - hardly a solid base from which to decide on an action to take. You may not feel like it now, but knowing that at some point in the near future you probably will, why not train yourself to act in your own best interests more consistently and get better at taking the right action at the right time.
Finally, there's a great quote from Harvard psychologist Jerome Bruner that it would help to keep in mind: "YOU'RE MORE LIKELY TO ACT YOURSELF INTO FEELING THAN FEEL YOURSELF INTO ACTION." So, as they say in AA: FAKE IT 'TIL YOU MAKE IT!!
*There is a third major part of the brain, the brain stem, which controls such automatic functions as breathing, digestion, and "fight, flight or freeze" responses. It is often referred to as the "reptilian brain" because it's the part of the brain that evolved first and is highly dominant in the lower animals (fish, amphibians, and reptiles) whereas the prefrontal cortex evolved much later and forms the largest part of the brain in mammals, and particularly in humans. However the brain stem cannot be considered a "thinking" part of the brain.