How does the next paragraph end?

How to become an optimally functioning person
Select a goal you can commit to.
It's been said that practicing for 10 , 000 hours on something will help you perfect a skill. If you can't put in that kind of effort, you'll likely fail.
Therefore, choose something that you're willing to put in time and effort to work towards. For example, you'll need a lot of time to train if you want to run a marathon.