A childhood belief about reading

When i was young, maybe 8 or 9, I had seen the movie 'The Bodyguard'. And in that movie, they mentioned that the bad guy had 'masturbated' on the bed of the victim. Well, my dad was driving me to school one morning, and i asked him what maturbate meant. He got really angry and told me it was a dirty word and that i should never say that again or think about that! I eventually looked it up in the dictionary at school, and still didn't understand it...what the heck was 'manually stimulating oneself to achieve orgasm' supposed to mean to an 8 year old?! So i just wrote the meaning down in my diary. My then teenage brother ended up stealing my diary, and when i asked him if he had seen it, he said: "Masturbation?" Talk about embarressing!