You are blame that to others some time, because circumstances are hurts you, or actually blame on you, but you are not accepted it, and put this on others. By this type of thinking your Joy convert into your Sadness, because than you are not able to accept own existence in this world. So you need to try convert own thinking to make Happy in all circumstances, by accepting it with happiness.
You and Your thinking is only reason behind that of you Joy and Sadness, if you blame it for that to others and also give credits for that to others, than think that, "The only reason which is exist behind that also your thinking!"

