When Matt Damon's character climbs over the tree the real Benjamin Mee, Milo Mee (Dylan in the movie) and Ella Mee (Rosie in the movie) can be seen as the first family in line. In the scene, Benjamin Mee is wearing what appears to be a Dartmoor Zoological Park cap, which is the actual zoo in England on which the movie is based.
During the first pub scene an old TV is showing a soccer match where a goal had just been scored by Brian Talbot for Arsenal. This was a significant English FA Cup final match in 1979 between Arsenal and Manchester United where with minutes remaining Arsenal snatched victory to win 3-2 ending a thrilling final.
The trivia items below may give away important plot points.
At the end, Benjamin Mee takes his children to where he met their mother, he takes them through that day's encounter, where Benjamin worked up the nerve to talk to his future wife with "20 seconds of courage," asking her why such an amazing woman would talk to someone like him. His wife responds, "Why not?", echoing the reason why Benjamin bought the zoo in the first place.
In the memoir on which the film is based, Katherine remains a predominant character up until her death halfway through. In the film, however, her character is dead from the beginning and appears periodically as an apparition.