* Developing believable characters: Spinelli excels at creating characters who feel real and relatable, despite their often difficult situations. This likely requires a deep understanding of human behavior and motivations, which can be challenging.
* Writing about sensitive topics: Many of Spinelli's books explore themes of loss, grief, bullying, and social injustice. It can be difficult to portray these complex issues in a way that is both honest and appropriate for young readers.
* Maintaining a youthful voice: While Spinelli writes for children and young adults, he doesn't condescend to them. He uses language and themes that are age-appropriate while still maintaining a sophisticated style. This balance can be tricky to achieve.
It's important to remember that every writer faces challenges in different areas. While we may not know the specific parts of writing that Spinelli struggled with, we can appreciate the effort and skill he put into crafting his compelling and impactful stories.