I went to the first grade one morning and they told us what apostrophes were that day. I went home at 3 and turned on the TV. Electric company came on and they explained what apostrophes were on TV. I thought they just came out. I never forgot that. You'll find that happens to everybody all the time. They think nothing happened ever before they noticed something that happened. It's nuts.
Also, considering it was the first grade and that's no exaggeration, I find hmanvolfan's post rather horrifying.