Why does the globe tilt 23.5 degrees?

When the director visited a school and saw a globe in the classroom, he asked student A, "Tell me, why is this globe tilted by 23.5 degrees?" Student A was very scared and replied, "I didn't do it." At this moment, another student B came into the classroom. When the secretary asked again, student B replied, "You know, I just came in and didn't know anything." The director asked the teacher doubtfully what was going on. The teacher said apologetically, "It's not their fault. The globe was already like this when it was bought. " Seeing that the director's face was getting uglier and uglier, the headmaster immediately explained, "What a pity," the headmaster said apologetically. "Because the school has limited funds, we bought a bargain."