The wisdom of Master Jedi Knight Yoda is indeed vast but his greatest morsel is one of powerful brevity, "Do or do not, there is no try." This is more than just a pep talk to pull your X-Wing out of the swamp (something that happens to me all the time). This is a statement of COMMITMENT and should not be taken lightly.
"Do or do not, there is no try." Yes, it's so powerful that I'll write it twice. You see, it's really quite brilliant. Do what you set out to do and commit your mind, body and resources to achieving this goal...or don't, just decide. If success is your goal, then anything less is not acceptable. Now, please note that I didn't say you will always be successful. You might and you might not, but the important thing is that you are committed to achievement. If you succeed, fantastic, that's you wanted. If you don't succeed, fine, you just found a new way NOT to get there, also a positive. The difference is that your dedication was there and you didn't cheat yourself. TRY is a weak word and implies a weak action, "an attempt". DO is an affirmative and it commands attention. Tell yourself that you're going to DO it and your mind and body will come together to achieve this. You can feel the power by just saying it. What happens if you tell yourself you'll TRY?

Do this one small thing for me, eliminate the word TRY from your vocabulary. Just erase it. And the next time someone asks you to do something you say either "Yes, I'll do it." or " No, I won't do it." See how different it makes you feel. Heck, just thinking about it gets me excited.