The psychic realm is not separate from this world we know; it is the same world, just in more detail.
There are many things we don't notice. Our senses, our feelings, our thoughts have limitations - and most of those limitations we have put there ourselves. We see only so much from the psychic realms.
Sometimes we don't notice the psychic realm, because we don't think about it or because we didn't have a conscious experience that would require us to pay more attention to it. Sometimes it is quite the opposite: we do have an experience but it scares us, so we just sweep it under the rug or lock it in the closet and throw away the key.
Maybe the most important thing to realize about the psychic realm is that it is not "out there" - it is "in here".