Thursday afternoon, Demong became the first American to even win a gold medal in Nordic combined. That night, his fellow American Olympians selected him to carry the country's flag at the closing ceremonies. Demong, who also proposed to his girlfriend Thursday night, called it "a whirlwind of a day."
ABC News caught up with Demong a few weeks before the games to learn his secret to success.
"Obviously the food at some of the hotels we stay at in these small towns is a little bland," Demong said. "So we bring a lot of peanut butter for packing lunches on race day, and hot sauce to spice up some bland food."
Demong also brings his own coffee and a press, and he's outright giddy if he finds eggs and bacon. In January, he was in France and was often served plain pasta -- the perfect time to use the Tabasco and Cholula hot sauces to add some flavor.
"If you stay at a one-star or two-star hotel, you get one- or two-star food," he said. "At this point in my career, I've learned to adjust"
At the Olympics, there are plenty of food options so finding food you like isn't the challenge. The biggest problem with the Olympic Village, Demong said, is the "massive amount of food" and learning how to craft a healthy diet.
This year's games in Vancouver mark Demong's fourth Olympics. He competed in Nagano, Japan, Salt Lake City and Torino, Italy, but did not medal.
The United States doesn't have a great history in Nordic combined, a mix of cross country skiing and ski jumping. But this year, the U.S. came into the Olympics with three world champions, including Demong, on the team.
"It's been a long road for U.S. Nordic combined. We've never won an Olympic medal before," Demong said before the games.
That finally happened on Feb. 14 when American Johnny Spillane won silver in the sport's first event in Vancouver.
Demong had a disappointing ski jump and came into the cross country part of the competition a very distant 1 minute and 18 seconds behind. He made an amazing comeback, finishing less than 18 seconds behind the leader.
"He looks better than anybody right now," one TV commentator said of his performance, halfway through the race. Demong ultimately fished sixth.
Then Tuesday afternoon, Demong gave an impressive show in the four-man team relay.
The American team was 14.1 seconds, behind the leading Austrians when Demong took over the relay for the final 5-kilometer leg. After 1.7 kilometers, Demong narrowed the Austrian lead to 7.3. By 2.5 kilometers that lead narrowed to 2.2 seconds. At 4.2 kilometers into the race, Demong closed that gap to just six tenths of a second. But in the end, he fell back and finished 5.2 seconds after the Austrian team, leading to a silver medal.
And then finally on Thursday, in his last appearance in the Vancouver Winter Games, Demong won gold, pulling off a victory after starting off 46 seconds behind. Fellow American Johnny Spillane won silver. It was the first gold medal ever for the United States in Nordic combined.