And: it has to be ‘continuous’. E.g. in ‘real’ water, the molecule of H2O ‘colloquially’ known as ‘number 12345678998776165441’ which sat next to molecule known as ‘number 1’, still has to sit next to it. All be it in a different location. I think something like mayonaise would have been a better example, as water molecules that are ‘next’ to each other can in reality split up quite easily by itself. While something like mayonaise would not.

*off course, quantum mechanics and all that suggesting that it would be impossible to label the individual molecules.