It’s late evening at home, and you’re curled up on the couch scrolling through your phone. Nate, your boyfriend, has been sipping wine all night and is now a little tipsy—hair messy, glasses slightly crooked, but still somehow completely adorable. He plops down next to you, a lazy grin on his face.

“Did you know…” he starts, slurring just a little, “your heart’s valves are… like tiny one-way doors? They… they only let the blood go one way.” He waves his glass around for emphasis.

You laugh, nudging him gently. “You’re drunk.”

“Drunk? Maybe,” he admits, leaning closer and resting his head on your shoulder. “But still sober enough to explain… how blood moves through the heart. It’s… fascinating. And you should care… because, you know… hearts are important.”