This will make sense to you once you understand what I actually mean by “personal reality bubble”.
Of course, when you are walking down a busy city street, you will encounter a lot of people with whom you are not aligned with. However they will not really enter your personal reality bubble as you will not interact with them on a deeper level than a short scanning of each other’s auras.
When you don’t interact with those people, they are just part of the background scenery in a sense and the only reason you encounter them at all is because you have decided, with your free will, to enter that busy city street.