Very good point.
"Love" is truly hard to define. I would have to say, without going on forever, here is a brief crack at.
It is wanting nothing more than to do right by the other person. To put their feeling before your own. To see them as part everything you do and plan on doing in life. For them to be your true best friend above all others in your life. When they feel sad, you feel sad. When they are happy you feel happy. You find them the most beautiful person in the world, which comes from much more than just looks. For you to imagine a life without them and it makes you choke.
That is a starting point. You say we "chose" to love each other. I do not remember making that choice. I remember many choices in life but that is not one I remember making. I did chose to date her and get to know here better. To listen to her story and find out all about here life and what she loved and hated. I did chose to let my guard come down and trust her. To let her become part of my life and future plans. I did not choose for her to become my best friend, it happened as a result of our time together. And this is what I feel about falling in love. You do not choose it but it happens as a result of experiences and time together.
But, what I am saying is why marry before that happens and hope for it then? Why not find that first then let it continue to grow?