The stuff we arrive on the planet with

Hello everyone. I have a question.

In the following passage, what does "the stuff we arrive on the planet with" refer to?

Recovery from addiction, as I know too well from my own experience and from the stories I've heard from others in my work, is a lifelong process. The learning never ends. It takes most of us a lifetime to establish and maintain a stable, mutually nurturing, and rewarding relationship with someone we love and, even then, we don't always do it well. The past traumas and family of origin dysfunction that cause or contribute to addiction, the fanciful thinking, and sometimes just the stuff we arrive on the planet with often combine to derail our most ardent and committed intentions.