Kim Hyun Joong looks back on his school days and part-time jobs on 'Happy Together' [article excerpts]

Well-known for his '4D' way of thinking, Kim Hyun Joong shared, "During elementary school, I was smart enough to wake up at 6 in the morning to solve math problems. But later in my school days, I let go of studying without a second thought and started working part-time jobs."

He revealed, "The money I saved from when I was younger plus the money I earned from my part-time jobs accumulated to about 100 million won ($89,400)."

Kim Hyun Joong also revealed that female customers used to leave their phone numbers on the receipts for him.