If someone asked you ‘why’ you love your SO, partner or a crush, you could probably list a bunch if their nice qualities and things about them that you appreciate. But that is not WHY you love someone, because you can list the same qualities in a bunch of other people you don’t love. In fact, someone you hate can be extremely talented or compassionate. Your feelings towards or for someone does not change them.
These qualities and traits is probably something you noticed *after* getting feelings of love and affection. Love is funny and amazing like that; it will open your eyes and heart, and is not something you can ever control with your will or thoughts. It will also make one go the extra mile.
As far as I can tell, love just happens based on factors I do not understand entirely. Also, I think love and compassion is our basic nature. Humans are complicated, relationships are usually difficult, not always compatible, but often worth it.
Love is love. Not in a naïve way where everything goes, but in a very basic human way, and there are as many ways of expressing it as there are people.