As a time traveler, it only took Li Ning one meal to go from planning to just hang around for a day to working hard to improve.
Because of what?
Because the food in the Wizarding World is too, too, too--yucky! Coming from a food paradise, he couldn't stand it. So he has to work hard to earn money and live a better life.
Li Ning swore that his plan from the beginning was to make more money and live a better life. It was as simple as that.
Mission: Life and food cannot be let down.