Mistakes are the most fascinating design element.
It seems to me that mistakes which occur during the actual design process are a synchronicity...... with??
I have this picture in my mind of a grid, and this grid symbolises all the rules, constraints and theory that you can pour into a piece of work... meticulous detail, exact penwork (e.g.), perfect alignment...then.....reaching for your coffee, you knock a can of red paint all over the piece.
Well...why is the most important question. Your body is a highly accurate mechanism... you can manipulate precision instruments, put on mascara without blinding yourself.... you are fully aware of how much time/money/prestige you have invested in this 'grid', this piece.. Then you pour red paint all over it.
"It was a mistake". End of story?? I think not, not at all. Synchronicity, not mistake.
"I don't need this !!" ...hmmm...well, maybe I do. I try and listen, more now than in my past, to what my mistake is trying to tell me.... and if that sounds a bit weird... I can clothe it in theory.
Your unconscious mind has a suggestion on the piece that you are designing, but you aren't listening to it because you haven't reached that "zen" state where things flow. ...so.... your unconscious is gonna make you listen.
It is a great design tool.... a mistake... don't ignore it.
It's everyday magic.