I believe I do, to the extent that I'm not in turmoil over the subject, but it's really hard to put into just a few words that could comprehensively cause every listener or reader to fully comprehend the concept.
There are different types of love for different relationships. The Greeks understood this. They had several words for love whose definition related to the relational context in which that love was found: Brotherly love, friendship love, romantic/sexual love, the love a god bears us, and so on. These are our cultural and societal structures for love.
Astrology and personality tests (Psychology) seek to define love by compatibility. That there are things inherent in our natures that make some easier to relate to and bond with, while others present a challenge. This is the place from which our feelings of love spring. Then, there are things in our nurture that can cause us to either be healthy or unhealthy in our ability to relate well to others. This is the place from which our personal concepts of love spring. The interaction of our natures and the circumstances of our nurture playing heavily into which type of loving relationship we find ourselves in with those around us if, we enter them at all.
The Bible frames love as more universally applied, not relational, but as choice and action: Sacrifice of one's self for the benefit and betterment of another (The example of Christ), that love chooses to behave well toward others so that no matter what relationship you're in, love can be tangibly observed (1 Corinthians 13:4-8). This idea of love can extend from the natural easy connections, the ones we happily choose to love, right on down to our enemies. This is what love looks like.
The Lover's wife formally accused him of not knowing what love is. A rather unfair assertion as, even when you think you know, love is one of the most profound of human experiences. I'd wager it's hard for any honest person to fully wrap their heads around and confidently proclaim, "I know what it is".
Her assertion came from the place of hurt over his choice to betray their marriage bond. He didn't behave lovingly toward her when he committed adultery. It's a valid hurt, but an unfair doubt to place in his mind.
I'm not entirely sure the Lover does know what love is in some ways, but I have observed him loving me and others in his life enough to know that he's capable of it. However, he's grappling with defining and understanding it for himself.
I tend to agree with the three sources above and I see how they blend together to give clarity to the concept of love.
Defining the type of relationship: Is this the general kindness that I should feel for mankind and politely show? Is this the love that I have for my familial relationships - the love for people I did not choose for myself? Is this person a friend? Is this person a romantic or sexual partner? Is this a relationship with a higher being?
Observing Compatibility: Is this person compatible with me? Do they fit in the type of relationship I feel I want with them? Do we have healthy boundaries? Can I work out relational issues through discussion with them? Is who we are together enhancing and helpful to us both or destructive and harmful? Are my feelings for the person compatible with our realities? Do I really see the person for who they are and do they really see me? Do we like what we see? And, so on.
Making a Choice and Acting On It:
Those you didn't choose (ex. family, co-workers, society) and their compatibility with you: You learn to make choices that make it possible to be well related - "loving" to the best of your ability - when you have to. This leads you to either stay close or put an arm's length between you and those over whom you have no relational choice.
Those you do choose (ex. friends, lovers, spouse) and their compatibility with you: You chose them because they work in the relationship realm in which you found yourselves. You gave the relationship time to evidence compatibility. This leads people to either choose to stay with those people or leave them behind. And, once a choice to stay has been made, loving them becomes a conscious series of choices in behavior to keep that love and watch it grow.
But, even that is simply an understanding of how love may happen and work well. To really define it is almost incomprehensible. I get a sense that, when I think about it, I merely brush against the foam of a vast ocean lapping up against the shore of my mind's limitations. It's a worthy pursuit but don't beat yourself up too much if you can't fully comprehend it. No one can so, we all just do our best to live it.