In this poem, Keats came across problems in the life of human being when he compared things with a life of that nightingale. Sitting under a tree he was admiring the greenish and fresh feel which was making him happy with a bird’s song, he was enjoying the beauty of nature. He was sad though, thinking one day we all will die. He was wondering while sitting under the tree that bird’s song is immortal and was feeling ecstatic. He was saying that beauty is not that what we see the real beauty is what we feel from inside. The beauty that was a fascinating poet was nature and that beauty makes him feel sad when he was thinking about an end of life and that is death. He will die, but the beauty of bird’s song will always be there. He was trying to explain that in this world nothing is static and time changes, nothing is permanent, neither a love nor a beauty.