If you didnt see it and many of us had trouble finding it. then your mistake really is not that obvious. But I know how you feel and I know that it will always bug you that the mistake is there. Sometimes its hard to live with the mistake because we strive to make a perfect quilt. I used to point out to others my " oopps " in some of my quilts and people would tell me they never saw it. So I decided not to point out my short comings because people really don't notice.