The Bic pen trick works wonderfully, and quite a few laptop locks still use the same kind of key. I got lucky with the speed, but my dad lost $20 to me in less than 30 seconds when his $20,000 warrantied lock opened without the key.
The file is the house. The DRM is the lock. If you have a key to the house, you can see what's inside. Just like if you have a key to the DRM, you can view the contents of the file.
DRM tries to keep people from making off with the stuff in the house after you've already let them in through the door.
DRM schemes seem mostly to be misunderstandings about how encryption and authentication fit together.