There are risks involved with having either one of these perspectives. Certainly there is a continuum of where you may fall but many people tend to lean towards one view or the other. Being extreme in either viewpoint has its challenges.
THE FALLACY OF “THE ONE”
I call it a fallacy because there is not just one person, or even five. The fallacy that being with the person you're with is the only shot you have at a happy life involving a successful, fulfilling relationship is frankly, completely inaccurate. Holding the belief in “the one” is mainly problematic to those of you that find yourselves in relationships that are no longer mentally and emotionally desirable. Yes, holding this belief can occasionally help you feel grateful and appreciative of the romantic relationship you’re in that is going really well. More often though, it can be harmful by creating a lot of unnecessary fear and pressure around the relationship working out. Further, if a relationship has ended, you may feel that you lost your only chance at love. That's about as high stakes as it comes.
WHAT IF I’M MISSING OUT ON SOMETHING BETTER?
On the other end of the continuum, you may think “there’s always a better option around the corner.” The belief that “there’s always another one” can be a helpful viewpoint if it helps you to remain hopeful about your love life, no matter what. If things don’t work out with one person, there will be other options. This idea is most useful if you can manage to have it after a relationship ends. It can even be useful during a relationship if it keeps you from having a sense of desperation about your relationship working out. The problem arises when you think of this a little too often you’re actually in a good relationship. It keeps you from being totally in the relationship and wondering if you could “do better” when in fact you’re missing the opportunity to be grateful for a relationship that you entered for a reason (or hopefully multiple reasons). Each of these two errors (in the extreme) can be directly related to the next concept.
YOUR BREAK-UP RESILIENCY
The fear of endings (or lack there of) is related to your break-up resiliency, an important factor to consider when you’re entering a relationship, in a relationship, or considering leaving a relationship. I define your break-up resiliency as your ability to recover from the ending of a relationship and bring your attention into the present moment in such a way that when you meet new people, your past isn’t haunting you with a gray cloud of fears. Determining the factors that increase your break-up resiliency are just as important when you’re in a relationship as when you’re starting to date after being single. This gives you the confidence to make more accurate decisions and see the strengths and weaknesses of your relationship more clearly. Simply look at what has helped you in the past when things ended and appreciate how difficult experiences have already helped you deal with loss. Remember that you do have coping skills and you will always be okay not matter what.