And I say, "Why do you say that?"
"Because there's a big sticker on the box that says 'May cause headache'."
"Does it?"
"Yes."
And after dinner I checked, and so it does! May cause headache, plus random other fun side-effects.
So yeah. Fear how totally observant I am.
Just now I took some analgesics at the same time as my nose spray. We'll see if that works better than waiting until the headache sneaks up on me...