Suppose we think of someone often, his thoughts affect us. For example, if someone is sad and you were thinking of him, you will feel sad within a few minutes.
Similarly, if someone is happy, those who think of him will also be happy. So what can we do if we want to be happy for a whole day? We can think of God.
Because God is the Ocean of Bliss, we can be immersed in Bliss when we remember Him. This is the smart choice.