Most religions teach that we have a choice between being selfish (bad) and being selfless (good). Surprisingly, Buddhism doesn’t do that. The Buddhist principle is the “two benefits”—what’s truly good for me is also good for you, and vice versa. You can see this in your own life. When you have love and kindness toward yourself, it is easy to be compassionate and kind toward others. And when you are loving to others, your own life is joyful and happy. This is the case for all positive emotions, thoughts, and acts. They always have two benefits—for others and for yourself.
The reverse is also true. The selfishness we normally identify as negative is always the result of greed, anger, or ignorance. Anything driven by these three poisons harms ourselves as much as others. In the end, there’s no contradiction between your best interests and those of others. Pursue the enlightened self-interest of love, compassion, and gentleness, and both you and everyone around you will benefit. It’s the great win-win.