Is it normal i sometimes re-write lyrics to songs?

I like to re-write lyrics of songs in my head sometimes... like the other day I took the Queen song "Tie your mother down" and changed the lyrics to "Call your mom a fag". I kept repeating the lyrics in my head like "Call your mom a fag! Call your mom a fag!" Then I imagined what a music video for that song would be like... it can start off with some young kid trying to convince his mom to go to the movies but she just says no. Then it cuts to Freddy Mecury and the gang playing cards back at their hideout when all the sudden an alarm with a flashing red light goes off. The music starts playing, and they slide down a pole to get to their car, they get over to the house and in slow motion Freddy slides across the car. Then it shows a scene of a wall being broken down and Queen comes through rocking out "Call your mom a fag! Call your mom a fag!" as they use they use the mic stand and guitars to point at the mom with the little kid smiling and pointing along.