One day towards evening when it was getting dark, two friends Yankel and Berel saw something in the distance. Yankel thought that it was a bird while Berel claimed that it was a cat. To resolve their dispute they decided on the following experiment. They would throw a stone at the object. If it flies it must be a bird, but if it remains still, it is indeed a cat.
As soon as the stone made contact with the object it flew away. As Yankel was about to claim victory Berel turned around to him and exclaimed: "you know my dear friend, it is the first time I have seen a cat that flies".
We are currently in the "Omer' period between the two festivals - Pesach and Shavuot. Our sages teach that this is a time of personal growth - to develop, refine and work on our character. But our personality is often influenced by our mindset - our perceptions and interpretations of ourselves, others and the world around us. Our perceptions become our reality and we respond accordingly. When we try to grow and improve we must first be willing to let go of our current mindset and be prepared to see things in a different way.
Once we accept that the cat is really a bird then we can take the next step.