Self-discipline is the ability to get yourself to take action regardless of your emotional state.
Just as everyone has different muscular strength, we all possess different levels of self-discipline. Everyone has some — if you can hold your breath a few seconds, you have some self-discipline. But not everyone has developed their discipline to the same degree.
The way to build self-discipline is analogous to using progressive weight-training to build muscle. This means lifting weights that are close to your limit. Note that when you weight train, you lift weights that are within your ability to lift. You push your muscles until they fail, and then you rest.
Similarly, the basic method to build self-discipline is to tackle challenges that you can successfully accomplish but which are near your limit.
It’s a mistake to try to push yourself too hard when trying to build self-discipline. If you try to transform your entire life overnight by setting dozens of new goals for yourself and expecting yourself to follow through consistently starting the very next day, you’re almost certain to fail. This is like a person going to the gym for the first time ever and packing 300 pounds on the bench press.
If you’re very undisciplined rightnow, you can still use what little discipline you have to build more. The more disciplined you become, the easier life gets. Challenges that were once impossible for you will eventually seem like child’s play. As you get stronger, the same weights will seem lighter and lighter.
Don’t compare yourself to other people. It won’t help. You’ll only find what you expect to find. If you think you’re weak, everyone else will seem stronger. If you think you’re strong, everyone else will seem weaker. There’s no point in doing this. Simply look at where you are now, and aim to get better as you go forward.