My daughter showed me a leaflet with five very different monsters on it.

R: “Which one do you like best?”
Me: “That yellow one.”
R: “No, that’s Daddy’s favourite.”
Me: “Okay, that orange one.”
R: “No, that’s my favourite.”
Me: “The green one?”
R: “No, that’s someone else’s favourite.”
Me: “How about blue?”
R: “No. That’s someone else’s favourite, too.”
Me: “Purple, then.”
R: “Yes.”
Me: “What if I like the purple one and the yellow one.”
R: “No! You can’t like two monsters at the same time!”
Me: “What if Daddy and I both like the yellow one best? I’m sure he won’t mind.”
R: “No! It’s Daddy’s favourite. Can you guess which one your favourite is?”
Me: “Purple?”
R: “Yes! Well done, Mummy.”

That taught me.