I was chatting with my brother and he used the phrase "emotional baggage", and my twelve year old niece asked what it meant. And as we tried to explain ("it's the emotional things you carry around like heavy luggage" "it's like when someone treats you badly so you expect everyone else to treat you badly even though they're completely different people") it struck me that the concept just wasn't meaning anything to her, and I really hope that continues for as long as possible. I'm not sure at what age it kicks in, maybe late teens.