I have not been quilting as long as you by any means and I see all of my mistakes as well, some take longer to notice than other, I left one I knew about in the quilt I did for me, it was intentionally left, I figured that I am not perfect, my quilt doesn't need to be either.
I had a truly blank spot last night while quilting, I was doing a block that I had never done before, looked at the picture, naturally picked the pieces up and put them together like HST, the thing was they were not HST but QST. so there I was picking them all out, I had finished the whole line of them before I noticed, so that was done, picked them up to start putting them together again and did it exactly the same way, good thing I didn't get through the first one before knocking myself on the head. So I laughed at myself, called me a few names, and went on to do them the right way.