As the years pass, we all aquire knowledge about a lot of different things. Some of it continues to be useful in daily life: how to walk, your friends' and family members' birthdays, how to file your taxes and renew your license plates, how to ride a bicicyle. There are a lot of skills that we learn that become obsolete as our life leads us down different paths: why sucking your thumb is comforting, the location of the girls bathroom in the elementary school, social pecking orders in high school. These things are shoved to the back corners of the warehouse in our heads to collect dust and cobwebs. Occaisionally, we pull one of these old memories out, dust it off, and then smirk about how far we've progressed.
The progress of piece of knowledge from active duty to a peaceful retirement can be gradual as its usefulness dwindles. It can happen abruptly when you move or graduate and leave a part of your life behind. And sometimes, you can try your best to cover it up and force it into an early retirement. That way you can start fresh and pretend total ignorance about things that you would really rather *not* know.
Most of the skills I have tried to get rid of are work related: the ingredient list for many of the sandwiches on the Arby's menu, how to pop movie theater popcorn, Crystal Reports. I'm afraid if I admit too much knowledge to some of these things, that someone will force me to do them again. I have decided to add Rational Robot to my list--for those of you non-geeks this is a tool for writing automated tests for software. You write scripts that launch other computer applications, run them automatically, and verify that everything is working ok. It's really really really really really boring. It's also one of those stupid skills that once you're proficient at, everyone asks you to do it ("I hear you're good at xyz--I have a project for you"). Never mind that it drives you batty, and that you feel like a trained monkey would be just as good (and wouldn't be as easily lured to surf the internet and write about it's boredom in a blog).
Lacking a trained monkey, I should probably return to my desk, and continue honing a skill that I will never ever admit to knowing (if only my manager and team leads didn't already know....)