I don't know if I have said in this thread before or not, but,
[SIZE=5]There are no mistakes in knitting![/SIZE]
What occurs are design elements that we did not initially plan on. If we like the new design element we keep it, if we don't like the design element, we save the idea for possible latter use, frog back to a good point and work on other new design elements.
The pair of socks I am now working on have had about eight new design elements that I decided not to use in this design.
True I could finish projects faster if I paid more attention to the intended design elements, but, I knit for fun, not speed.