Brush up on your physics history
"That bit just sounds liike hype - resistors, capacitors and inductors are passive devices, the behaviour of which can be simply described in terms of the rate of change of current with respect to voltage."
Sure, resistance, capacitance, and inductance are the three most well known of the four passive electrical component properties, because their effects dominate at the physical scale where we normally fabricate practical electronic components. OTOH, folks that work with nanoscale electronics are well aware of the hysteretic effects of memresistance.
If you took any graduate-level electronics physics classes, you'll recall that in 1971 Leon Chua published an well-known paper in which he reasoned from symmetry arguments that there should be a fourth fundamental element, which he called a memristor (short for memory resistor). However, although he showed that such an element has many interesting and valuable circuit properties, until 2008 no one came up with either a useful physical model or an example of a memristor, mostly because nanoscale electronics technology wasn't far enough along.
It was Stan Williams' paper in 2008 that showed, using a simple analytical example, that memristance arises naturally in nanoscale systems in which solid-state electronic and ionic transport are coupled under an external bias voltage. These are the results that serve as the foundation for understanding a wide range of hysteretic current–voltage behaviour observed in many nanoscale electronic devices, and for the practical device development being done by Stan at HP.