Single people blunder through this world looking for that elusive thing called chemistry, yet the current stats for divorce indicate that chemistry is a very unreliable indicator of potential.
I am not saying that we should ignore this sense of “rightness” but the fact that people get it wrong so often tells me that it needs a closer look.
Everything we do in life is driven by our internal value systems: we look outside of ourselves and we like what matches our values and reject what doesn't. So in a nutshell, this mysterious chemistry is us responding to what we think matches up to our values. Chemistry is undefinable because our values are unconscious.
People with like value systems experience chemistry
The trouble is, in this fast-paced world of ours, we have little time for getting to really know someone, so our value judgements are made according to the external (looks and current behaviour). Looks can be deceiving.
On the other hand, there is what we call “opposites attracting”, which, in my opinion, never happens
Sure opposite magnetic poles attract, but we aren't magnets. What you see in this case is, for example, a woman who has “learned” certain behaviours, but has a differing value system (remember, values are unconscious) being attracted to a man whose behaviour (again, learned) matches up to her value system. Or the wild child with a value system different from her current behaviour being attracted to the “nerd”. In reality you are actually seeing that woman's value system embodied in the looks/behaviours of that man.
Chemistry can be “felt” with a complete stranger, so long as we have enough visual information to match up to our value system
What often happens is that over time the value system is revealed and the chemistry disappears as there really is no value compatibility after all. I see the value difference taking its toll in relationships where there are increasing fights and “pulling apart”, often for reasons the participants don't understand.
Knowing your own values can take the guesswork out of “attraction”, as you will understand why you are attracted to so and so, and if it is valid or baseless. It will teach you to look for what is beneath the surface as well as what is on the surface. It will help you steer the relationship in a direction of mutual discovery, instead of just wanting a good time.