LOS ANGELES—On a 14-hour flight to Tokyo, an irredeemably egocentric woman constantly reclined her seat into the lap of a recently divorced man, making him think that she was romantically interested in him.

“I thought, the man in front of me is an asshole,” said Patrick Bates, 42. “Then I noticed it was a woman, and I looked at the back of her head and thought, wow, she’s attractive. I thought, why is she in my lap? Does she like me?”

Not wanting to appear creepy, Mr. Bates allowed the woman to recline her seat throughout the entire flight, and even made sure not to turn on his blindingly bright reading light lest he disturbed her sleep. To that end, he also sat still throughout the entire flight, never once getting up to use the lavatory.

Mr. Bates remained hopeful about love and imagined numerous hypothetical conversations with the woman for more than 14 hours, until they parted ways at an x-ray luggage scan checkpoint in Tokyo. He thought about her the entire day.

The woman was unaware that Mr. Bates sat behind her.