Impossible?

 Challenge yourself with something you know you could never do, and what you’ll find is that you can overcome anything. ~ Anonymous

What could you never do?
My first answer is to run a competitive race.
I’ve never done that. And my tale of running at all
was of trying to break a Red Rover line
crying because I’d run to the prompt,
“Let Fat Domino come over.”
And having carried surplus weight all my life
running on arthritic knees sounds excruciating.
Yet last week I walked twenty-three and two-thirds miles.
And I’m no longer morbidly obese, not even obese,
just overweight. It’s not likely I’ll run in a competitive race
but I don’t qualify as a fat domino, either.
What you’ll find is that you can overcome anything.