Where I disagree slightly with Emerson is that when you give happiness you get more than just a few drops of it back. Often, when you do something that makes people you care about happy, it returns even more happiness back to you. So it increases the happiness all around.
You can allow yourself more than a few drops and let in the flood of happiness as you keep the ever-increasing energy of joy in your life by spreading it around. The benefits of this are immeasurable and healing to the planet. Happy people do not go around maliciously destroying each other and selfishly plundering resources. They look for creative ways to keep the positive energy flowing.