If you can say "Oh yea that makes sense" with the same set of knowledge you had both before and after some event happens, all else being equal, you have an expectation. That is enough for placebo.
You have to have literally 0 knowledge about an event to rule out placebo.
I drink lots of water. Lots and lots, to the point that it’s already kind of annoying how frequently I have to piss. I’m fairly skeptical that drinking yet more would yield any benefits.