The Proximate & Ultimate Reasons For Human Behaviour.
"Natural selection favours certain behaviours but doesn't necessarily favour us having explicit awareness of why we do what we do" ~ Dr Tania Reynolds
To properly understand human behaviour, we must understand both ultimate and proximate explanations. Ultimate explanations are concerned with why a behaviour exists, and proximate explanations are concerned with how it works.
Put another way, proximate is the more immediate "reason to" do a behaviour ~ sex feels good and gives you pleasure and love.
Ultimate is the "reason why" the behaviour was shaped that way by evolution ~ it creates offspring who continue your genetic line. Here are some other examples:
Why we like fats and sugars in our food. Proximate ~ it tastes good.
Ultimate ~ it provides ancestrally rare, energy rich, high calorie sustenance which should improve our chances of survival.
Why we like symmetrical faces in our partners. Proximate ~ they look attractive.
Ultimate ~ symmetrical faces are genetically harder to create and indicate better quality genes would be passed on to our potential offspring
The reason TO and reason FOR these actions are not counter to each other. Now revisiting Dr Reynolds' quote - One problem with having the veil of ultimate explanation-ignorance lifted from our eyes is that it makes us feel less agentic, less in control of our own desires, more cynical, contrived and manipulative.
The answer to this discomfort is to find humour in it I think. You have to laugh at the absurdity of being a sovereign creature who feels like they have their own will, but is being largely driven by millennia-old preferences to help you survive and reproduce.
"Ultimately happiness comes down to choosing between the discomfort of becoming aware of your mental afflictions, or the discomfort of becoming ruled by them"