Artwork from the trobairitz, or female troubadours
Love is strange. Nobody's quite sure what it is, and if you read dictionary definitions for example they tend to describe love as some form of much stronger affection i.e. it's not defined in itself but in terms of something else, normally affection.
In the medieval era, the nobility developed a conception and practice of love sometimes called 'courtly love', although it was rarely called that in its day and what it exactly was is still debated. Many modern ideas and images surrounding romance and love stem from this time. It was not usually a love between man and wife but rather between noble men and women. It was secret, and not sexual, with the aim being to achieve a new type of relationship that sat somewhere between erotic desire and transcendent experience.
It seems a strange set of ideas and practices to the modern world, where love and erotic desire for example are usually felt to be two sides of the same coin, unless the love is between members of a family. And there's very little talk about transcendence or some type of higher experience in relation to love these days, again it's usually thought of as just a stronger form of affection. And is contrasted with lust, which is seen as more uncontrolled emotion and feeling.
It would be difficult for somebody today to claim that they loved somebody who wasn't their partner or member of the family, and at the same time had no plans to sleep with them, for example. People would suspect their motives. They might get away with it in the general sense of maybe it being a close friend, "I love so-and-so, they're such a good friend to me". Like a sort of imitation familial love.
One of the strange things about love is that it tends to be understood like peak oil, as some sort of finite resource. For example take happiness as an emotion - nobody thinks that if you're happy because of one thing you're doing, that something else that makes you happy will then take some of that other happiness away, as if there's only a certain amount of happiness available and you have to ration it out. And yet this is what gets done with love all the time, there's an assumption that if you love one person, then you must have used up some of your love-stock, re-directing it from one person to another. This is completely at odds with all of the talk about the importance of love in the world, how we'd all be better off if we just loved each other a bit more, etc. Love is almost fanatically territorial, in the way we often practice it. It can't be used up, it can be continuously built up over time so the 'stock' is always getting bigger.
This might all look a bit disingenuous of course, like a call for 'free love' and swingers parties and so on. The problem with those sorts of things is that they're reactive, the usual model of taking what's currently done and just reversing it, as if that suddenly makes it more interesting. In reality it just makes it equally uninteresting, in the opposite direction. What the courtly love folk were trying to do was invent a completely new way of loving, which at times became a bit silly with the various chivalric devices, but then everything can be taken to extremes. They were after something between friendship and the traditional ideas about love, something that wasn't about sex or the marriage contract or even about friendship - something powerful but not quite so territorial as the normal ideas about love. Something much stronger than a friend but less tied up with all of the contractual and territorial issues surrounding lovers.
Courtly love could be said to be a denial of the importance of the body, and this was in fact a motivation for many who took part, based in their Christian ideals about the transcendence of the spirit and evils of the flesh. But you could imagine a type of courtly love that included the body, some sort of mid-range affection between a handshake and sex. At the end of the day though it's still not clear exactly what love is, and how it's different to something like affection. It's often a strong feeling, and a lasting, unconditional thing where you accept a person completely for what they are. So it seems less to be about feelings than about some sort of ongoing interplay of differences between people, that reinforce the relationship between them rather than causing it to break.
Just like some chemical mixtures cause explosions and things won't mix, while others will.