Uncle Li wasn't short of money; he came to work as the school's gatekeeper simply to pass the time.
Back when Sang Chuan got into a fight with someone in the gatehouse and accidentally broke his flowers, although Uncle Li was upset, he knew the fight had started because Sang Chuan was protecting a female classmate.
So he let it slide, didn't make a fuss, and didn't demand compensation. Sang Chuan knew the flowers were expensive but had no idea just how costly they were.
Uncle Li didn't exactly hate Sang Chuan; he just felt they were utterly incompatible, like oil and water.
Sang Chuan wasn't just mischievous; he loved teasing Uncle Li and always seemed to inadvertently cause him harm. When Sang Chuan dropped out, Uncle Li was so thrilled that he celebrated by setting off fireworks for several days.
He thought better days were ahead, but lo and behold, Sang Chuan returned to school!