Sometimes it's just fun to write code that's hard to understand.
Many years ago (early 90's) our company was taken over, so we knew our days were numbered.
We used NCR mainframe they used IBM. They wanted our system on their hardware so we had to convert it to IBM.
To those not familiar with the subtle differences between the NCR & IBM ideologies.
NCR people were jack of all trades, we would load printers with paper, operate the machine, do system analysis, write efficient code.
IBM people were "I don't write code, I'm an analyst", program running slow - buy more hardware.
Anyhow, we re-wrote our system using recursion in COBOL, knowing full well they would hove no idea what it was doing.
Sometimes it's the little things that give the most pleasure.