Title text:
Other numbers are largely unaffected, but anyone using '4' for their certificate key is urged to upgrade to '5'.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3314/
I've slowly learned in life that every system, every design we rely on was thought up by other humans a LONG time ago, never updated or replaced with something new, and is within inches of crashing and burning at any single second.
If you think I'm crazy (don't worry, I most certainly do) spend a calm afternoon examining the support columns of your local bridges.