A familiar relationship can feel deeply convincing.
You know the person's moods. You know how an argument usually ends. You know what to say to calm them down. You know what not to mention at dinner. You know how long they disappear after conflict. You even know the exact kind of apology that will bring the relationship back to normal.
None of that proves the relationship is healthy.
It proves you know the system.
Familiar is not the same as safe
Human beings learn patterns quickly. Once a pattern becomes predictable, predictability itself can reduce anxiety.
That creates a strange effect. A relationship can be painful and still feel easier than leaving because you know how the pain works.
Healthy safety feels different.
You do not feel safe because you have become skilled at avoiding someone's reactions.
You feel safe because truth is allowed.