On the December 18th episode of SBS' 'Strong Heart', actor Yoon Shi Yoon revealed the hilarious story behind his nickname, "Study King Kim Learning".

'Flower Boy Next Door' co-star Park Shin Hye shared, "Like a word addict, [Yoon Shi Yoon's] hand never leaves a book. Whenever he's learning something, he learns from a book first. That's how he became known as 'Study King Kim Learning'," which is a reference to his previous role in the drama, 'Baker King Kim Tak Goo'.

It was also revealed on the show that Yoon Shi Yoon owns around 1,500 books. The actor opened up about incidents that occurred because of his habit of learning everything from books.

Check out a clip of Yoon Shi Yoon discussing his 'Baker King Kim Tak Goo' role below.