Lately, when I make a mistake, I assess it and see if it would be ok to leave it alone. 99% of the time I will fix it. The other one percent of the time, I really try to leave it alone because I am trying to stop being a neurotic perfectionist since quilting and sewing is supposed to be fun. Also, I really would like to eventually finish a quilt. One percent of the time is a big improvement for me. I really need to attempt two percent of the time soon. :) So I guess my answer is No, I would never make a mistake on purpose. :)