Years ago, I enjoyed some inner tubing on a lake. A boat pulled me along, and its wake created an arcing, bouncing ride.

Someone on the boat gestured over the noise of the water and the motor. I gave the thumbs up: all good here. The speed was fine and the ride was fun.

Soon after, we were going faster and wilder.

Again a check-in. Yes, I was good. A little rougher than I’d prefer, but still fine.

Upon the third check-in, and another increase in speed, I gave a hands up gesture indicating I was ready for someone else to have a turn.

Back on the boat — slightly battered — my friends laughed with delight. “We couldn’t believe you kept wanting to go faster!”

From my perspective, thumbs up meant, “All good.” From the boat’s perspective, thumbs up meant, “Go faster.”

Sure enough, as I watched a video of myself bouncing along, every time I gave a thumbs up, I heard someone off screen saying, “He says go faster!”

Shared language. With it, we communicate. Without it, we might ask for one thing and receive something quite unexpected.