More than a decade ago, a newspaper ad for a strawberry farm in Beijing somehow ended up being used in an English exam for middle school students across China. The ad included the phone number of the farmer, Mr. Wang, and that's where the story gets interesting.

Ever since, Mr. Wang has received a steady stream of calls from curious students who stumble across his number while taking the test. Even all these years later, he still gets around 10 to 20 surprise calls annually from kids all over the country.

Instead of ignoring them, Mr. Wang picks up every time. He chats with the students, encourages them to study hard, and often ends the conversation with an open invitation: "When you graduate, come visit me in Beijing."

Most kids probably assume he's joking. But one student took him up on the offer. Years after first calling as a middle schooler, the student visited Mr. Wang in person and was rewarded with a celebratory Peking duck dinner.

The best part? Mr. Wang's phone number is still on the test. So until someone updates that exam, he'll keep getting random calls from students and keep serving as an unexpected mentor to generations of test-takers.