What you are actually capable of likely differs from what you think you are capable of. You likely believe yourself capable of many things that exceed your actual capacity, and you likely believe that you are unable to do many things that you actually could. Without knowing your strengths, you won’t live up to them. Without knowing your limits, you will cause yourself and others unnecessary suffering.
While the progressive nature of character precludes you from knowing the full measure of what you could be except through your successive attainment of the incremental improvements that will lead you there, there are ways to get hints as to the magnitude of growth that awaits you.
Here’s an exercise to help you expand the magnitude of what you think you are capable of that leverages the fact that it’s a lot easier to imagine how bad you could be than it is to imagine how good you could be: Imagine just how much harm you could cause the world if you had chosen to completely focus your whole soul on being the worst possible person you can imagine. Now, take that degree of harm and transpose it onto the side of good. That amount of good is probably far beyond what you imagined your potential to be. Why is it so hard to imagine, if the only difference is the direction in which you aim your whole soul?
You should think about what difference your life will make in this world. Far too many people make the world a worse place through the lives they choose to live, and still more manage to come and go without affecting any significant positive difference. High impact actions typically require sustained and significant intentional effort, and long and difficult efforts are rarely undertaken without a strong belief in an explicitly expected outcome. Every single person has the capacity to leave this world better than they found it, but none will achieve this without an intentional effort. If you want to make a difference with your life, you are going to have to think about what that difference will be, how to achieve it, and have a reason to believe it will be worthwhile.