Everything, without exception, is due to cause and effect.

Being asleep and mechanical is also a cause that creates the effect of being a "leaf tossed by the wind," thus some of what happens to us is just "accidental," in the sense that we are just being thrown around by the forces of nature (cause and effect in motion).

To know the source of the causes requires awakened consciousness and deep investigation. It is impossible to see them with terrestrial eyes. One must meditate.

It is good to know that divinity can manipulate the circumstances in order to manage the emergence of those effects. For instance, when we become serious about eliminating the ego, our divinity can "postpone" certain karmas, in order to give us a chance to work on ourselves and get stronger.