Let's say that life is pretty much ruled by chance. If things are going bad, well, you've run up against a streak of bad luck. If things are going good, you've run up against a streak of good luck.
You can apply this to your existence; right from the moment that that little egg met up with that little sperm. Happy accidents and bad accidents. That's all you have.
And you can have good intentions, and big plans, and lots of hopes and dreams, and then, well, you roll the dice on all that, and hope for luck to shine down on you.
It's as plausible as any other explanation for our lives. Kind of humbling... and maybe you're lucky to know it as a guiding principle. You roll the dice and hope.