In anything that you do, you will feel better and feel satisfied if you give your best. But sometimes after giving your best and you don't see any result.. you will feel bad, you will feel like you've just wasted your time and effort. Sometimes you will even feel like you've been cheated. You will feel like the whole world is against you, you feel like you don't want to try next time, you wanted to quit right away because you think that you don't have what it takes to win.
And once you believe that you've just wasted your time and effort... you wouldn't want to give your best next time. And that kind of mentality will make you a loser, mediocre and quitter.
But the reality is you really need to give your best in order to achieve your desired results and expectations. you need to give your best to become successful. If you will not do it then you will never achieve anything great in life. You will only get mediocre results. You need to give your best everyday, 24/7, 365 days a day.... no days off.
The best thing to do to maintain doing your best is to give it with no attachment. Give your best without expecting anything in return, give your all without expecting that you are going to succeed. So when you lose despite of giving your best... you will never feel bad, you will not feel sorry for yourself. You will treat what happened just like an ordinary plain day.
It is like pledging to yourself and making a commitment to just give your best no matter what. You will give your best regardless if you win or not. It is like making it a lifestyle, making it part of your everyday living.