Moods matter. The difference between being happy and being sad is your mood. The rest is all the same. Moods matter because they impact how you interact with the world. If you don’t pay attention to your moods, your moods will seem like a reflection of how things are. You will forget how things really are.
If you think things are how you feel about them, your interactions will create problems for you. If you see a cute and cuddly grizzly bear, and you feel so wonderful that you go tickle its belly, there could be problems. If you pay attention to your mood, you can observe your happiness and the grizzly bear from a comfortable distance.
It matters immensely if you are happy, sad, scared or angry. You should know what you are at all times. You do not need to congratulate yourself for being happy or berate yourself for being angry, but know what you are and know that you are much more than that.