The entire dynamic of life, the reflex that draws all sentient beings into life and, ultimately, to dharma, is joy. All beings seek joy. That’s why they do what they do. It’s as simple as that and that’s what makes us all the same.
When this is recognized, the seeming complexity of behavior disappears. Yes, karma builds up over countless lives, acting as a filter and veils of obscuration. People act out in this life formations of karma that were formed countless lifetimes ago. But when all is said and done, what is always being sought is happiness.
People engage in all manner of behavior, finding both good and bad fortune: the fulfillment of their wishes, the crushing of their dreams. But both these conditions are fleeting and transitory. The only source of true joy lies within. It is a simple message, constantly repeated by all beings who have spent any time on the subject. The source of all happiness, all wisdom, and all joy arises from the Self. It is the Self that is sought down every turn, down every road, down every alley. In every form, we seek the Self.