During WWII, the US government financed a series of Private Snafu cartoons. Using a wonderful sense of humor, they were able to convey important messages to the troops--and the films were not shown to the general public. You can tell this in a few of the films, as the humor is a bit more adult than you could have gotten away with in theaters. Today, you can find these shorts on DVD as well as for free downloads at archive.org.
The cartoon begins with Snafu doing a very boring job--separating shoes. He longs for an exciting job, like the ones done by his brothers, Tarfu and Fubar. At that moment, Snafu's fairy godfather appears and shows Snafu that these other jobs aren't quite so wonderful. I assume the message they're trying to get to the troops is that all jobs are important and not to gripe. It's done with a nice sense of humor AND a special guest appearance--but to find out more, you'll have to see it for yourself.
By the way, try looking up the terms snafu, tarfu and fubar--then you'll understand that these films were NEVER meant to be seen by the general public!