My son has quite a little collection of Matchbox cars. He likes to line up all his cars in the manner of a miniature used car lot. It’s a way to organize his ever-expanding empire and make its growth quantifiable.

The miniature car lot: Bad credit? No problem! Just go work your charm on Mommy or Daddy.

One day, while he was lining up his cars, a burst of generosity overcame him. “Here, Daddy,” he said. “I have a surprise for you.” He held out his hand in the way a child does when offering an imaginary gift.

I took his pretend present eagerly. I was happy that his head was not so turned by the success of his car dealership that he had forgotten his poor old dad.

“It’s a transformer,” he told me as he handed the gift to me.

“Oh good,” I said. “I love transformers.” I made some turning motions with my hands and some transformative sounds through my teeth. “Schwitt, schwitt, schwitt,” I said as I twisted the air between my fingers. “It’s a truck. Schwitt, schwitt, schwitt. Now, it’s a robot with a laser canon.”

The boy laughed. He was pleased with how well I understood the workings of his gift to me. “Do you have a surprise for me?” he asked.

“Oh yes, I certainly do,” I replied. I could give the kid these kinds of toys all day long. They are imaginative and economical, and that is just the sort of world I need to live in, even if it is make-believe and only lasts until our next trip to Target.

I quickly put my empty hand behind my back and pulled it out again, offering him all the treasure it held. He took the wonder from my hand. “What is it?” he asked.

“It’s an airplane,” I said, happy that I could give him something so nice.

All good things must end. What caused our precious moment to end is hard to know. The best I can guess is that a surge of petulant testosterone spiked up his spine to that reptilian spot in the brainstem of all little boys. Who can say for sure what it is that transforms the pleasant Master Jekyll into that nasty Hyde urchin in the blink of an eye.

He flung my gift away. “I hate airplanes,” he huffed. His cerebrum does not hate airplanes in the least, but a spastic, testosterone-drenched medulla oblongata is liable to hate anything and everything.

“Oh,” I said. “If that’s what you do with my presents, I guess you don’t need to get any more from me.” I looked meaningfully at his array of die-cast cars.

He followed my eyes to his cars. I could almost see self-interest tamping down the testosterone at the top of his neck. “Wait,” he said. “Can we do that again? Here’s another surprise for you.” He held out his hand. “It’s another transformer.”

“That’s so nice,” I said. “I love it.” I drew out the word love as I gazed my meaning into his eyes. “And here’s another surprise for you.”

He took his present out of my hand. “What is it?”

“It’s another airplane.”

He stared at his hands for a moment, too proud to love his imaginary present and too wise hate it. “Let’s play with my cars,” he said after he had given the problem in his hands just enough time to evaporate.

Somewhere between pride and humility there lies a sanctuary of comforting die-cast vehicles. Diplomacy is a complicated playroom.