The only people who have a chance of creating an intensely happy relationship are those who enjoy living alone and dig being single. Those who are terrified of singlehood will, in all likelihood, end up in miserable relationships. Such people never manage to end unhappy relationships and can never move on because the fear of being single makes them cling to something that clearly doesn’t work.
“But what if there is nobody better out there?” is the pathetic motto of such people’s lives.
A person who digs being single has an answer to that, “Then I just go on being happily single. Yippee-doo!”
If a happily single person meets somebody s/he likes, s/he will find it easy to defend his or her interests and boundaries. The fear of “what if I say / do / choose whatever I want and get dumped for that?” is simply not there because there is no value in being in a relationship for the sake of it. Only a happy, fulfilling relationship that is good enough to convince the lover of singlehood to abandon the contented single existence will be acceptable.
Of course, if you cannot be happy living with just yourself, then how do you expect anybody else to be happy living with you?