Belief

 Everyone is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid. (Albert Einstein) 

An octopus in a birdcage what an unusual sight. We all know the octopus can easily get out of the birdcage. However, the octopus is told he can not so. Therefore, he does not try. Thinking his whole life that this is his home, this is his station, in life, these are his abilities, so he sits in a birdcage out of place. We let this happen to our mind when we listen to OTHER people dictate what we can and can not do.