I thought I was going to finish the doily in November. It'd be tough, but I thought I had the time and energy available for it. Then I found an error. Not an itty-bitty error, something I could live with. I already had one of those. (It's the single trc where it should be a cluster of three)
No, this one was major, not fudge-able, and two rounds down. The two longest rounds of the doily down.
I skipped a treble-crochet cluster shell stitch, and had to rip back 3.1 grams, ~35 yards, and more hours than I'd like to count of work.