Mental toughness is one of the hardest characteristics to develop. Navy SEALs have a 40% rule which they live by. It says that when your mind is telling you you’re done, you’re really only 40 percent done. That’s why 99% of runners who start a marathon finish even though most people hit a wall ...
If you have something that is important to you, then eliminate the unrelated and unimportant tasks, get started no matter how big the challenge, and commit to your goal.