What's the name of this poem?

I only know that it was written by a Russian poet. It's about how he was unhappy and he was blaming the environment. So he changed cities, but he was still unhappy. At the end he realized that there weren't cites that were making him unhappy, it was him all along. And then he sees that if we want something to change, or want to make something better we must always look and start from ourselves first.