In all of history, Leeuwenhoek’s discovery of the microscopic realm might well be the closest anyone has come to falling down the rabbit hole, climbing through the looking-glass, or stepping into a wardrobe and finding oneself in a world of fantastical creatures.
It is interesting how microscopes were not originally intended for scientific use, rather for commercial enterprises. It's funny that the most important discovery of mankind - bateria therory, viruses, etc. - came about on a whim. This further's the author's idea, in reference to Freud, that we are not truly in control.