I've been sitting here reading this, having a little chuckle to myself (not at the serious bits, honest) when my son walked in. "What a you laughing at?" - "Oh, about how brutal honesty isn't all it's cracked up to be." - "Yeh, I worked that out in grade 4. When they say 'no offence' you know what's going to come next will be offensive."

I think that effectively establishes an age limit on brutal honesty.