smarter than the average bear

To be smarter than the average bear means you have the ability to trick and fool some of the other bears in the park but you will still have to be on your toes to get ahead of this one, which refers to the leader. This phrase is referring both to the average bear and the not so average bear. What it means figuratively, is that you may be smarter or more cunning than the average person, but when you get to a person who can look past this, you will have to be more careful.