Curious George was a cartoon monkey on Forrest’s shoulder talking to him.” In the 1994 classic, Forrest’s (Hanks) favorite book is an old version of the “Curious George” book series.

Each September, publisher Houghton Mifflin Harcourt celebrates another year with Curious George by declaring Curiosity Day, which takes place this year on Sept. 14. In honour of Curiosity Day ...