I don't really understand how parents actually want their kids to do what is considered 'normal' kid stuff like sneaking out and etc instead of doing dumb, 'nerdy' things. So they WANT their kids to misbehave? Ok. That's cool, I guess.
Thankfully, besides the random references that only I understand, my parents are really supportive of my hobby. They enjoy watching my brickfilms when they are finished, and think they're really creative. So, naturally they understand when I want to spend all my money on buying BIONICLE sets and don't even blink when an 18 year old puts LEGO on his Christmas/Birthday lists.