Sex ed in 4th grade? Never! It doesn't start until 5th grade here, but I skipped 5th grade and Sex ed wasn't a topic that I studied at home over the summer. So I didn't learn it until I was 10 years old in 6th grade. At that time, it was learning about what sex was. 7th grade and 8th grade were STDs. 9th grade was STD's and (finally) a bit of anatomy. But we never learned clitoris. This is the first time I've heard that term.