YMMV / Numberphile

• Never Live It Down: Matt Parker, and his Parker Square. It has turned into a Running Gag and a bit of shorthand for a valiant failed attempt.
• Tear Jerker: A final video with game theorist Elwyn Berlekamp was uploaded on April 23, 2019; he had passed away on April 9. Many viewers expressed their condolences and sorrow. It was a bad shock for viewers who didn't know about his death before watching, since the video doesn't mention it until the end.