Ask HN: What's your worst programming blunder and/or code you're most proud of

This was a question that went around at a monthly team social meeting, (might be common for all I know) but I thought it incited some good discussions/laughs.

I pushed a "fix" (what ended up being breaking changes) to our demo environment 20 mins before a company wide demo. Fortunately I live in a terminal, so I was able to ssh in and spam cli commands + vi fast enough to get things going again with only a slightly awkward introduction delay. I also neglected to remake the MX records when migrating our domain, leading to a few days of email silence.

Nothing too bad tho, all things considered. Would love to hear other's responses.