TIL: Your "identical" strings might not be identical — the NBSP trap. P.s. translated from gemini.
Spent way too long debugging why exact-match comparisons kept failing on strings that looked 100% identical on screen. Same font, same spacing, copy-pasted from the same source even.
Turned out one string had a regular space (U+0020) and the other had a non-breaking space (U+00A0,  ) between words. Completely invisible in Excel, in a browser, anywhere — but == treats them as different characters.
Where it came from: I was pulling text from a web app (Angular-based), and devs had used   in the markup to stop certain phrases from line-wrapping. Every time I scraped that text, the "space" came along as NBSP instead of a normal one. Meanwhile my reference data (typed manually) used regular spaces. Cue silent match failures with zero visible cause.