My Bad and Unaffecting Parodies.

I keep doing these, in my head. I hear a song, like it,  parodize its  words (mostly partially),  hum it for a while and then gradually forget it. Then I hear it again, like it again, parodize it again & forget it again. The funny part the original and repeat parodies are quite similar to each other, almost never comical (which a parody usually intends to be), they are a almost just the original song with some of its words replaced making it queer, unaffecting and almost always less appealing than the original song.
But i don't know why, but this has occurred so many times that I am going to write them to rid them off my mind.