That longed-for "chemistry" — the one whose dizzying effects you are desperate to feel in the gap between the man and the woman on a first date — I do not think much of it.
That elusive, thrilling spark everyone writes about, and far worse than that, the spark everyone uses as the criterion for how suitable the person sitting opposite them in the pub is, is no more than a combination of sexual attraction and some random signalling from your unconscious.
A date is supposed to begin a patient, friendly process called getting to know someone.
If you do not understand that you came on a date to get to know a human being, you are better off not coming. Even if you are only looking for a fling. The truth is that deep down you are desperate for a relationship and terrified of dying alone, but you have persuaded yourself that all you want is sex.
A date is the basis for acquaintance, and acquaintance is the basis for readiness.
And mutual readiness is the genuinely wonderful thing that has to be created between two people who do not want to be alone.
But in the meantime, as long as you are not running a laboratory at a research institute, do me a favour and do not talk to me about chemistry.
Go out into the fields and the pubs and get to know people. It is fascinating.