Working with stone sometimes gives us the opportunity to craft something that is not just useful and functional but also creative. Creativity among other things involves taking risks. It is often a trial an error thing. That's how we come up with new things - how we make things, including mistakes. The worst mistake is to think something we've done is good or worth keeping just because we did it. Just because we are trying to be creative doesn't mean we are.
Isaac Bashevis Singer wrote “The wastepaper basket is the writer’s best friend. ”
Our medium is stone. It's where our ideas are expressed. We don't discard the stones but ideas sometimes have to be thrown out to make room for better ideas. In any case we should be thoroughly editing our own stuff long before anyone else sees it. This is not a bad thing. Walls can be taken down to make room for others.
Because dry laid stones are not set in concrete, we have little excuse for letting a 'creation' of ours stand if we know it to be unworthy.