When I watched Tex Avery's "The Village Smithy", I assumed that it was an original idea created by the Termite Terrace crowd; I was more than a little surprised when I read on IMDb that it was based on a Henry Wadsworth Longfellow poem! But no matter whence it came, it's quite a funny cartoon, as Porky Pig works as a blacksmith's assistant and inadvertently sends his boss on the wildest ride ever.
There have been numerous instances in which I've seen a spoof of something while having no idea that it's a spoof. Certainly a number of these instances involved Looney Tunes/Merrie Melodies cartoons (I saw "What's Opera, Doc?" long before I'd ever even heard of Wagner's work). It's also happened with "The Simpsons" (I remember when Maggie hit Homer on the head with a mallet and red paint flowed down a drain; only later did I see "Psycho" and get the reference). There are many pop songs that I only learn about because I hear "Weird Al" Yankovic's parodies, and many B-movies that I only see on "Mystery Science Theater 3000". I wouldn't be surprised if many members of my generation encounter the spoofs of famous works before encountering the originals.
But anyway, this is a pretty funny cartoon. Porky sure did some neat stuff during the two years when he was Warner Bros. top cartoon star.
I bet that we all miss some things when we're not looking.