The nature of True Love is this: to know that this person exists, and have the fact of his or her existence free you from having to be sad, anymore, ever.
Anything less is mere human love, and requires a ton of work to maintain.
A followup thought occurs to me now that I've spelled those out:
Only one of the two can ever be prepared for.
Thank you, goddess of love, for glimpses into your perfection and the strength to build and steady our bright-hearted imitations of it.