We all have certain desires and undesired outcomes related to whatever possible course and attitude we take in life, whether it be at the larger macro scale (what shall I do with the rest of my life?) or at the micro level (as in, what route shall I take to work this morning). These include all the myriad choices we make each hour and each day. These choices determine our karma and our destiny. It's no accident, nor any great mystery, how this evolves; although one would have to utterly omniscient to understand all the many gross and subtle interconnections and causative links that determine happenings and outcomes.