I am almost 25 years old and have been reading these since I was small enough that I couldn't reach them at my public library since they were on the top shelf. Tom is such a good protagonist, Hettie is the child-free "grandma's friend" that everyone needs in their life, and Hugo is a spoooooky ghost friend that causes harmless chaos. 15+ years later, I still love this story and I plan to keep re-reading it (and the rest of the series) any time I need a potato chip book.