His cage is a pig sty (no pun intended), this much we already know. Yet he was jumping around ecstatically as if it were the greatest day of his life. If I couldn't tell the difference between hay, poop, food and bedding I don't know that I would be acting so joyful. I tried coming up with a few possibilities for his recent elation. They're neither extensive nor legitimate in any way.
1. He's happy to be alive. The sheer joy life brings him is enough to put a little hop in his step no matter what environment he is living in.
2. He likes living in filth. Maybe all this time we've wasted hours and energy cleaning his cage when he really does enjoy a home that I like to call "lived in."
3. Popcorning has multiple versions/meanings. A bad popcorn could very well exist, and in this case my 2 previous reasons would be completely inaccurate.
4. He wasn't popcorning at all. Maybe he was just so god damn pissed that we FAIL as caretakers that he couldn't hold it in and decided to run amuck fervently in the 2' x 2' cage he calls a home.
My best guess: #4. Again, I have accepted my shortcomings as qualified to care for animals.