Yes very true !
My son is in grade one and couldn't imagine him learning that at the age of 6.
I believe we started in grade 7? Can't recall.
Your son doesn't know that girls have vaginas and boys have penis's? Maybe we're different because I have a boy and a girl.
The only thing on that I have a problem with would be the anal sex teaching. I personally feel that's a tad too far because done improperly it can cause extreme problems.
And let's face it, the Internet is out there. Just place yourselves in your kids places nowadays. They need to be made aware of a lot more in the world by us, the parents. If we try to keep them in the dark, they'll just go ask Mr. Google.
My 12 year asks me some crazy questions and I answer as truthfully as possible. He told me that his friends thinks he's crazy for asking me the things he does, but he doesn't care.