Why does "The One" matter? Oh yeah, humans and animals have a duty to
procreate. The spiel of the simple "meet someone, fall in love, get
married, buy a house and have kids" creates that hole from childhood.
"The One" would fill that hole. This implies L.T.R.
Spent time over the years
thinking about that hole and trying patch it up with duct tape as I
realize I don't need to do any of those things to be happy. "The One"
isn't that one you'd find and marry (or common law) the first time
unless you are extremely lucky or tolerant. Each one is a roll of the
dice.
There's a difference in "The One" for everyone just like beauty is in the eye of the beholder. They are moving targets as well. Sure you could be happy now that you found someone who could be "The One", but will you continue to be? Needs shift as life progresses and you meet new people and do new things as well as shed people and old things. As that shift happens, needs for happiness shift. Typically, you'll work through it (Talk, Therapy, etc.) and find ways to change "The One" to fit your newfound needs. If those needs cannot be met then the relationship is informally over soon as the next "The One" comes in or when it comes to a head.
Since people change fast and slow,
"The One" likely to never been the one forever as long as the laundry
list of needs doesn't shorten over time. Could be that "The One" needs to be more or less clingy, communicative, sexual, stylish, cleanliness and/or etc. You could get angry, show stern looks, talk it out or help them forcefully, but it won't stick if "The One" doesn't see it as a big deal. Threatening to leave "The One" over small things only emboldens them when the threat isn't carried out. Even if you do carry it out, there is no guarantee of long term change. You'll have to lighten up the laundry list or get back out there, which is easier?
What I've learned from Bounty Hunter D's videos (Cheater lie detector videos: https://www.youtube.com/c/BOUNTYHUNTERD/videos) is that "The One" you'd thought you locked down made a decision to do something destabilizing to effectively end the relationship. This was "The One" for you, you keep that glimmer of hope and don't come to resolve why this and why that? The answer is apparent and unimportant. The foundations of your relationship crumbled and it becomes apparent with the blatant signs (this is worst case). Eventually, your partner's senses shift enough over time such that you are not "The One". You saw the signs early, but did not have the apparent evidence (not always true!) and ignored them because love. There's typically no way to break up peacefully when you feel you've staked a lot on the relationship. It is always better to find out early before the next step anyway.
Time
won't heal. Becoming numb is not healing. It affects your personality in profound ways and probably for the better. Likely you'll take less bullshit next time. Take time to find yourself. Focus on the more important things such as personal growth. More opportunities that you probably would have missed being in a negative place.
What is the "The One" for any specific person?
Is it "The One" in the movie? brings your fiction alive? Is it "The One" for the short vacation? "The One" to bring home to your parents?
Also why chase away your dream of "The One" by having a laundry list?