Why do I more or less seclude myself from others

Every choice of your personality will more or less lead to feelings of loneliness and separation. However, you feel much more at ease and more natural when you feel at one with other people. It is much nicer to live with people than to oppose them or judge them or use them as a big projection screen for all your standards and values and judgments. But opening up to other people means that some exchange is about to happen. The other person will express himself. And seen through the eyes of your personality, every expression comes with some form of uncertainty/unsafe feelings (maybe you are going to be attacked, what does the other person want from you, etc.) and a greater chance for unpleasant feelings (this does not meet my standards/values, he does not do what I want, interpretation of body language etc.)

So your personality keeps the other person in some kind of predetermined status quo he may not even be aware of. So you could say that your personality reacts on himself and experiences the limit he imposes on the world. He does not do that without any reason, it also contains some form of gain to him: a feeling of safety, of being in control, other people do not have power over him, that kind of ideas. And as long as you value these gains, you are likely to interpret and react accordingly.

One of the things I recently practiced was during a "new age meeting". On the street it was clear to me from a great distance which people were going to attend this meeting. And the remains of my personality did not consider that to be a good thing. And because he did not want to be associated with these people, it is very likely that he will not open up to any contact with these fellow-visitors. Now because I was aware of these feelings, I could consciously make a choice not to strengthen them. At the end of this meeting I really felt like having made quite a leap forward on this particular aspect of letting go of the ideas of my personality.

You bring this kind of attitude into all your contacts. You have a more or less predetermined mindset for the meeting you are about to attend, as well as when you are going to a bar or disco, go shopping or whatever. You have already determined where the dangers are and how you are going to deal with them, which usually is: no or limited contacts. You may get it by now: there is another way to look at all this: simply do not do it like that and let go. Thus you allow yourself and all the people involved to explore new ways of dealing with each other. And the outcome of that may surprise you in pleasant ways.