A few days ago, JT was playing with a tambourine. We had to leave to go somewhere, so we simply removed the tambourine from his hand. Up until now, such an action would've had little effect other than making him mildly confused. But no, he has object object permanence now. He understands that the tambourine was in his hand, and it was fun, and now Mommy and Daddy have done something to make the fun thing no longer in his hand.
He pitched a fit. I felt kind of bad when I smirked at seeing him cry, but I'd never seen him throw an all-out temper tantrum over a toy before. About being passed into the arms of someone who is not me, yes. But not over a toy. (Does this mean I'm on the same level as toys now? When do toys overtake me in importance? Did that happen already and I missed it?)
We did the thing we probably shouldn't have done and let him take the tambourine with him into the car. (Where it still is, I'm pretty sure.) I think the only thing I got out of this was massive relief that we cured him of his pacifier addiction a few months ago. (Quit the pacifier by six months old = best baby advice ever.)
What I Learned About Writing: It's not unusual for other characters to react in ways the protagonist never expected. This can happen if they gained new information. Whereas they might've seen the protagonist as a friendly entity before, this new information could paint the protagonist in a negative light for them. And that protagonist had better hand the tambourine back pronto before the character in question calls grandma.