If I were to live a thousand years, I would belong to you for all of them. If we were to live a thousand lives, I would want to make you mine in each one.
Michelle Hodkin
So Look at peoples qualities and behavior at first after you are comfortable together, you will start evolving based on each other. Then you can be attached to the human, not the quality, as you both are now considered almost like a single being, supporting each other.
The ship of Theseus (analogy)
Getting attached to actions or behavioral qualities that can change overtime as we are always evolving is disappointing.
But idolizing a human regardless of the behavior changes can be close to worship, which is not fit for a human relationship too.