While I'm no physicist, I like to think of such things this way. At the heart of much of physics in the everyday world - not necessarily in more complicated stuff like quantum physics - there is a principle which applies to most phenomena. "Nature is always striving to achieve a balance, or equilibrium". This applies as much to electrical problems as to anything else e.g. water or gas at a higher level or pressure, will tend to flow down to a lower level or pressure.
Therefore you could apply this to the refuelling problem of static build-up and discharge. Just think of wherever static electrical charges might develop for whatever reason and what conductive path they're most likely to follow in order to discharge to a lower potential (pressure). If there is a small gap created between a conductor or body with a higher static electrical potential and another conductor with lower potential, then the static will jump the gap.
It's not for nothing that physical science used to be called "Natural Philosophy". Here endeth the lesson.