From the way people speak and spell, I say you loose one year for every 5 you are out of school.... (I don't know but it sounded good)

You lose your childhood, I guess.

I remember select bits. I know what an adverb and adjective are, but I don't remember what a gerund is. I know how to speak properly, but I don't know how to conjugate a sentence. I can add, subtract, mulitply and divide mostly in my head, but I don't remember how to figure out the area under a curve. You're going to jettison alot of information from school that you won't need in your day-to-day life as a working adult. High school is primarily a primer for college, I think. It gives you a little taste of many subjects to let you discover which one interests you the most. That will guide you when you select a college major and thereby a career...you hope.

I kept studying every vacation and noticed that my classmates needed the first three weeks just to recall what they'd forgotten during the summer, allowing me to build momentum and forge ahead on it all year. Some highly technical subjects, such as higher math or a language with a different alphabet, may be completely gone; other things aren't. Your education is what you have left after you've forgotten the facts. But "use it or lose it" is generally true.

For me I lost ALOT of my education. I think it depends on how much of your childhood education you really use when you grow up. I still use math and reading but forget about social studies proper english. But really you never know what you might grow up to be so it is good to learn everything so you have alot of choices when you go to college and decide on a career path.

All of it! Ha ha.. just kidding. Honestly, I don't remember a majority of the stuff they tried to teach me in college. I remember a few things, usually things that I use or come across often, the rest is pretty much gone. Most of my high school knowledge is gone too. It's all very sad, really. All those years, pretty much wasted, since I don't remember anything. Oh well, at least the diploma looks good :)

From my standpoint, I am definitely "Smarter Than a 5th Grader" because I know most of the answers each morning on the Channel 5 news and don't need the multiple choice help. Whether I am beyond 5th grade is debatable. I took lots of secretarial classes in High School like Shorthand and Office Practice. Honestly, I must thank this mean old woman named Martha Blick for teaching me how to type without looking at the keyboard. It is the best skill I ever learned. Personal computers were in their infancy when it came to public schools, we had some Apple computers for "Word Processing" at the time and I did enjoy that class. English and Literature was great for me and I enjoyed Social Studies greatly. I dumped out of all Math and Science related classes as quickly as possible and a foreign language was not a mandatory requirement at the time. Suppose I slipped through in the nick of time. I was not college material and I did not get a NYS Regents diploma but who really worries about that when you have been out of school for over 20 years anyway. College would have be a waste of time for me and a waste of money for my parents because I am not a good student, I prefer to fly by the seat of my pants. I know when I am getting a good deal at a store and I know if they are shorting me change at the register and that is all I really need to know to survive.

I don't know I can't remember! Ihave retained what I use in life today, and I have learned a vast amount of new knowledge that I use today at work.

Of course you continue to learn all your life. The lessons come in different packages, however. You don't "lose" learning opportunities, you fail to take advantage of them. Consider, if you were to study any foreign language for 30 minutes each day, at the end of a year you would know more than you know now...guaranteed. You might even be able to speak the language. So, one year from now, remember this answer and ask yourself what you have learned in the past year.

Alot. Most of it. We can always go look up stuff or watch Jeff foxworthy's game show re 5th graders/ But what isn't mentioned in your question is what we gain by learning to think, to concentrate/focus, to question, to use logic and to integrate different concepts.