Today - well, yesterday in Korea at this point - was the first full moon of the new lunar year. The Korean name for this event is jeongwol daeboreum (정월 대보름; 正月大보름 in mixed script) and is marked by a couple of special events.
One of these is involves eating special foods - different types of nuts - as a ward against boils. This was something that our Korean teacher mentioned in association with the five important dates of the lunar calendar during a class discussion last year, along with some of the relevant vocabulary. Boils and abscesses are called buseureom (부스럼) in Korean and are said to be cured by the oils present in chestnuts (밤), peanuts (땅콩), walnuts (호두), pine nuts (잣), and gingko nuts (은행나무 견과?). Together these nuts are known as bureom (부럼), and are often given to children on the morning of Daeboreum. Cracking open the nuts with one's teeth was supposed to also have the added benefit of scaring away evil spirits for the coming year.
I didn't eat any nuts today but did have some peanut-flavored soy milk. Does that count for anything?
보럼. Photo from this page. However, it seems they stole it from elsewhere on the internet.
Another aspect of Daeboreum is that it is one of the three most important days of the Daoist calendar along with Jungwon (the 15th day of the seventh month) and Hawon (the 15th day of the tenth month). Traditionally known as Sangwon, it was a day when the Daoist deity was said to deliver his blessings, "so followers conducted rituals to their ancestors".
And on the subject of folk beliefs no longer practiced, it may also be worth mentioning bokheuk humchigi (복흑 훔치기?), or soil pilfering. From Seasonal Customs of Korea (Shaffer 2007:57):
The 14th was also known as Somang-il (Day of Small Wishes). Early in the morning, one would venture out to a well-travelled road, dig up some soil, and take it home to scatter around the house. This was done in a belief that this soil was fertile with the good fortune of those who traveled along the roadway, and would thus be fortuitous for the household. Intersections were favored sites for such digging. In Seoul, the Jonggak Intersection of Jong-ro was the most popular spot for the "good luck" soil.
Lower-income people observed a related activity, known as bokheuk humchigi (lucky soil pilfering), during the night of the 14th, when they would sneak into the courtyard of the wealthy to steal some soil and then scatter it around their house, especially in the kitchen, in a hope that the good fortune of the rich would be transferred to them. At the homes of the affluent, the house would be brightly lit on this night and servants on the lookout for possible thieves. This soil was coveted because the guardian spirit of the house, Teoju, was said to be contained therein.
Jonggak Intersection today is covered in concrete, but this photo from 1907 shows that it was a dirt road a century ago.