For the purpose of getting indecorous and sticky, and living happily ever after, two people used to be selected for each other by their wiser elders.
This did not work very well for those stuck with a partner that looked like the back end of a moose.
Another bad idea was the practice of saving yourself until you were married, because how can you know if you are compatible bashing your bits together, unless you try before you buy?
These days, young people would laugh at such practices, and old people would laugh right back, because what the youth are getting up to now is even more bizarre.
The night-time economy grew to provide a forum for the playing out of sex games.
Teens and twenty-somethings would go out on the pull, starting with a bucket of libation at a bar and then onto a club where they would gyrate themselves into an assignation with some young lovely that might come to fruition in one of their homes, or on the night-bus heading there, if they just could not wait one more minute.
Even in this scenario, some conversation would take place, a common ground would be identified and at least part of the decision that this was the person you wanted to be with for the rest of your life, or the rest of your night, would be made on the basis of their personality, not just how good they looked in jeans.
Today, that is all gone, replaced by the swipe. If you have been living in a jungle retreat for the past five years, or you are over 60 years old, let me explain.
The phones that people carry round with them, the ones they stare into all day while walking into traffic, are now sex finder machines.
There are applications that cater for those that want to share intimate photographs of themselves with others. Fortunately, the youth of today are richly endowed with pictures of themselves.
They take more selfies than they have hot diners, mostly because eating makes you puffy and the phone camera adds 10 pounds as it is.
Having uploaded a snap of yourself, others can then view, rate, discard, save, send a frowny face emoticon, swipe on to the next one or respond in kind. Two clicks later and you could be having wordless sex with someone whose name you do not know.
If you think that sounds impersonal, prepare yourself - it has just got worse.
Men are now cutting out the human element altogether and having a relationship with their phone, rather than using it to find a relationship with another person.
Teenagers, and others old enough to know better, are developing feelings for female and male-voiced digital assistants that come installed on their mobiles.
Ilya Eckstein, the chief executive of Robin Labs, a company that makes software that enables users to have a conversation with a computer, said his company's virtual assistant was used by some men for up to 300 conversations a day.
They are not talking about the weather.
He told The Times "As well as the people who want to talk dirty, there are men who want a deeper sort of relationship or companionship."
He said people "want to flirt, they want to dream about a subservient girlfriend, or even a sexual slave".
This is not what was envisaged by the pioneers of virtual assistants, such as the iPhone's Siri and Microsoft's Cortana.
They were designed to be used for asking your device to call your mummy, or to find the nearest Pizza Express. They were not made for lonely hearts to whisper sweet disgustings to a slavebot.
A writer for Microsoft's digital assistant Cortana, said that "a good chunk of the volume of early-on inquiries" were about the chatbot's sex life.
Here is spoiler alert: chatbots do not have a sex life. They do not even have bots.
We are at the precipice of another sexual revolution. Pretty soon the technology will cut out the middle men - us.
Chatbots will be talking dirty to each other, so we don't have to.
While you sleep, your digital assistant will make lewd comments to someone else's digital assistant about wanting to have its nodes cleaned, thereby cutting us out of the equation completely.
If our phones ever learn to take pictures of themselves, we're sunk.Suggest a correction