As the saying goes: don’t write unless you can’t not write.

There are so many better ways to spend your time. Pushing a boulder uphill is hard. If it never gets over the hump and starts pulling, find a different boulder!

I think the problem statement is: How do you know when to Let Go of the current boulder?

The poem suggested many many many possible when. Here's one: "unless it comes out of / your soul like a rocket,".

Unfortunately (or fortunately), in life, there is no methodology to prove that a given search problem is futile (e.g. NP-complete)... so we have to take our chances and choose. I believe that's the beauty of life: choice.