Sewing, One Day at a Time, and a Question

I finished that skirt.  Of course, it could not have been as easy as I thought.  I stitched on an elastic casing made of purchased bias tape - with the ends folded under - and inserted the elastic.  When I tried it on, I decided that I needed to narrow the skirt a bit.

After figuring out how much I needed to cut off, I laid the skirt out on the cutting table and just hacked it off.  I ripped out the casing's lower edge of stitching for about three inches to each side of the cut.  I opened up the casing, pinned the cut edges right sides together, and stitched the seam.  I followed this by zigzagging over the cut edges.  I turned down the casing and stitched it down along the lower edge.

Have you ever had to undo the work you've done on a project?