I've long wondered why, if you invent something - even something major - your patent is good only for a relatively short time (I think it's 20 years or so) and then you can renew it, but not indefinitely; whereas if you dream up a simple song like "Happy Birthday To You," your copyright can last for (now) 90 years after you're no longer gracing this planet with your corporeal presence.

Seems like screwed-up priorities to me.