Or, one person could be unavailable because he/she is already in a committed relationship.
Compare your degree of attachment/liking/closeness to a situation where all 10 contacts with the other person have left you feeling very unhappy.
Part of that romantic attractiveness dimension is physiological and a greater part is cultural and psychological.
For example, many people share beliefs that flowers, cards, "romantic" music or movies, lighting, and romantic talk are "romantic." Those beliefs cause a romantic reaction in the believer when any of those stimuli are present under the right conditions.
Why is it that two people become friends or lovers and others don't?
Following are some general causes that research has shown to be important.1. There may be many people "out there" who you could be good friends with or could be happily married to. They live in another city or a block away, and you never meet them.