What's the difference between "suffering" (辛 신) and "happiness" (幸 행)?

 ANSWER: just one thin line (一)

The Chinese character 辛 (신) means "spicy hot," but it can also mean "suffering," as in 신고 (辛苦), which means "hardships." And the Chinese character 幸 (행) can mean "happiness," as in 행복 (幸福), which means "happiness." The only difference between the two characters is that the character for "happiness" (幸) has one extra line (一 일) at the top. That one thin line difference between "suffering" and "happiness" is often just a change in attitude.

마음만 바꿔먹으면 고생도 행복이 되네.
"By just changing one's attitude, even suffering can become happiness."