OK, I think you will get a kick out of this. A few months ago I purchased a Schiit Lokius EQ to just add a boost to the treble when I am watching TV as I like running the cable box audio through my preamp/stereo.
Simple enough to do, even in a semi-dark room. No need to read the instructions.
For two weeks I was tickled as can be at how adding the EQ treble made the TV dialogue perfect and a lot easier to understand.
Only then when I took a closer look at the Lokius adjustment "symbols" on the unit and read the manual did I realize that I had inadvertently boosted the base and not adjusted the treble at all.
OOPS, confirmation bias at its finest..