The Simple Explanation proposes that our personalities are largely defined by the memes we cling to. These memes, and our reactions to them, contribute to our behaviors and subsequent karma.
In a previous article on Transpersonal Memory, the Simple Explanation suggests that memes constitute "vibratory patterns held in the zero-point field, and accessed through our minds. Furthermore, apparently personal memes are actually harmonics of collective memes and are shared in common with all who hold onto that meme. The particular shadings of one person's meme differs slightly from the next person's, as is to be expected among fractal replications of a single phenomenon, but all who hold it recognize its pattern and are affected by it."
(Ropp, Cyd C., A Hermeneutic and Rhetoric of Dreams, Janus Head, http://www.janushead.org/3-1/cropp.cfm )