In a previous post I mentioned not using negative lookbehinds during a regex party when another tactic might work better. Turns out that other tactic might not actually always work, judging my the amount of hair I just yanked out of my head, and oh yeah it also helps when you use the correct regex expression for the tool you're working with. So like (?<!nbsp) instead of whatever ineffective variant of that I was previously trying to use.
Jokes about the kind of drinks or snacks you bring to a regex party, now more welcome than ever.