In the Christmas carol that the staff was singing, they "received":
7 Giant Colons
6 Small Intestines
5 Prolapsed Hemorrhoids
4 Gastric Ulcers
3 Yellow Gallstones
2 Fatty Livers
And an asthmatic in the E.R.
This episode shows the first time Doogie shows his journal to anyone. He actually writes the entry while Wanda is watching.
Doogie knows Japanese, which he learned from the gardener.
At the age of four, Doogie's Mother realized he was able to learn languages very quickly when she took him to her Spanish class and by the end of the first week, he was helping her with her homework.
We discover Doogie had cancer and that Vinnie shaved his own hair when Doogie's fell out.
Continuity error: When Doogie's dad says "I have never been more disappointed in you than I am now." You can see Doogie in the back seat in the background looking straight at his father with no movement. A quick cut close-up on him shows him looking to his right then straight at his dad with no time to move his head.
Goof in opening credits: The second newspaper article shown says that Doogie graduated from high school at the age of 12 years old (after being in high school for 9 weeks). The third newspaper article shown says that he graduated from Princeton at the age of 10. So he graduated from college before graduating from high school?
Doogie was Born on the 21st September 1973