My mother always made chicken soup when I was sick with a cold/flu. I always felt worse afterwards and she would be upset when I told her because “that’s so unkind to say”, like it was a criticism of her cooking. It took me so many years to figure out that I am slightly allergic to celery which I was only fed when I was already sick …
I remember this working really well on google. Recently (several months?) it didn’t as I would expect. Fictional example: when searching for “asdf123” google would show results just containing ‘asdf’. One particular thing I noticed was that google seems to omit underscores from verbatim strings. So for example when searching for “asdf_qwertz” it would show results that contained asdf and qwertz without the underscore.