Some day I will be in an orchestra
I have played in an orchestra
Some day I will play a cello
I have played a cello
Some day I will be a musician
I am a musician
I saw a picture once that had percentages of success based on perspective.
"I can't" has no rate of success.
"I won't" has a little bit more.
"I will" and "I can" have some, but not 100%.
Leave 100% to the mindset of "I have already done it."
And do it.