when do people around you (friends and family around you now) learn about the human body?

when do people around you (friends and family around you now) learn about the human body? Interview someone who is "senior" (50 -as old as they get)' middle age (30-49) and 'young adult' (18-29). Compare their responses. Are there differences between the knowledge afforded to them and the words used to explain the sex-related body parts. Why/ why not ?