“Mindfulness is simply being aware of what is happening right now without wishing it were different; enjoying the pleasant without holding on when it changes (which it will); being with the unpleasant without fear it will always be this way (which it won’t).”
Whether this moment is happy or not depends on you. It’s you that makes the moment happy. It’s not the moment that makes you happy. With mindfulness, concentration and insight, any moment can become a happy moment. Happiness is an art.