Oh man...been there, done that! A couple years ago (when I first started out) I decided I had to make a mountain of quilts for everyone for Christmas and then got sick about halfway through. I was working on a quilt for my niece and I sewed a whole border on inside-out. Ripped it all out, pressed the fabric back flat, and promptly sewed it back on exactly the same wrong way again.
That was when I learned that my brain does NOT function when I am sick and I should stay far away from my sewing machine when I am not well!