"And then I saw civilisations in their millions, cruising the light fantastic"
I had this idea the viewer is witnessing this awesome spectacle for the very first time. A revelation that he/she has stumbled upon a mass intergalactic highway i.e. "The Light Fantastic"
Branching throughout the billions of star systems, the Light Fantastic consists of thousands/millions of distant exotic space vesels, luxury yachts and small personal liners en-route to innumerable destinations throughout the galaxy.
This is just one capillary route that ebs and flows according to gravatational pulls of nearby stars, planets and moons.
Fancy a trip on the Light Fantastic?