I thought bring street smart was, and I'm using the definition from Urban Dictionary,
"A person who has alot of common sense and knows what's going on in the world. This person knows what every type of person has to deal with daily and understands all groups of people and how to act around them. This person also knows all the current events going on in the streets and the ghetto and everywhere else and knows how to make his own right decisions, knows how to deal with different situations and has his own independant state of mind. A street smart person isn't stubborn and actually listens to things and understands it."
There's nothing bad about being book smart, but you need to be out there in the world and know how it works in certain situations If you're only book smart and go out there in the world, you're pretty much naive and fresh meat to be taken advantage of.