First, we find that high standards in relationships are not bad. Everyone deserves to be happy and everyone can freely define what that means to them. If that means you will not be content with anything but a doppelganger of your favorite movie star with the personality of a saint – so be it. Everything is good. It only becomes a problem if you do not realize that your standards are too high. If this is the case (and you do not), this article can hopefully help.
1. You have never had a long-term relationship
You could have had many good friends, many short relationships, but never something that would last for a while. Not inherently bad, but when the common thread is "No one was good enough and there is something wrong," remember that your standards may be too high. It is quite possible that you were just unlucky with the people you met, but also – maybe not?
2. You judge people. Very much
In general, judgment is not a good trait. And it is one thing, if you judge, you know about it and you agree with it. It is a completely different matter if you judge, and it will be difficult for you to meet new people, make new friends, and make new relationships. If your response is to judge people and look for what's wrong with you, it will be hard for you to avoid loneliness. Just make sure you do not overcorrect. It's better to be judgmental than not having a "filter" for the people you spend your time with.
3. You have standards that you do not even know
As I said – high standards are not a bad thing. You can have high standards and live your life for them, looking for people to fulfill them. Which is terrible if you have standards that you do not even know. If you did not think thoughtfully, "who's right for me," you're constantly finding an invisible wall to find things that you do not like in random moments.
4. Your friends are great
Finding friends (and generally meeting new people) is much easier when you are younger. When you're younger, you're surrounded by so many people at school, in the area you live in, and more generally in life. And there are no "social norms" that stand in the way of starting a friendship with them. With your high standards and high probability of meeting new people at a young age, you have probably met many people who meet your standards and are now your friends. And they are absolutely great. They are supportive, they are nice, they speak the same language as you (figuratively and literally), and it is a pleasure to be around them. The only problem is that they are friends and you are looking for something more than that.