You can make some big changes instantly.
For example, you can decide, right now, to go vegan. From one moment to the next, you can decide never to consume animal products again. You could also transition to veganism slowly—which is what I did—but you can make the change instantly.
Other big changes can only happen over time. You cannot instantly become much stronger than you are. It’s simply impossible. Instead, you have to lift or move heavy things many times—perhaps a month of lifting before you can see any change in your body.
So when you want to make a big change, first ask yourself whether it’s a change that, by its nature, can only happen with sustained time and effort.
If the change you want to make requires sustained effort, beware of quitting too soon.
If you want to lose weight, don’t go to the gym three times, notice you haven’t lost a kilo yet, and then decide it’s not working. If you want to increase your confidence, don’t read a book on that and try the suggested techniques twice before pronouncing the book worthless.
Better yet, decide in advance when to evaluate your progress (and thus the efficacy of your technique). Decide after a certain time, or after a certain level of effort. Say, after having made 25 visits to the gym.
Or, if you’re looking to become a better blogger, after writing a blog post every day for 30 days straight.