F**k macro ring

I recently bought a extension tube for my DSLR camera as a cheap way to play with macro photography.
Today, I attached it to my lens, and wasn't pleased with the results (it may very well be due to my missing experience with it).
But the real tragedy then started when I tried to remove it from my lens. It just stuck on it.

I carefully tried to remove it for 20 minutes.
No success. Bummer.
Starting to get upset about it.
Took a short break to cool down.
Tried to use pliers. Starting to apply more force.
Still no success.
Getting angry.
Showing it to my girlfriend.
5 minutes later, she had it removed without pliers. Yeah!
Be happy again.