If spirits (people) can show themselves and communicate with us briefly, why don't they do it more often? Why don't they just walk up and have a conversation? I've asked myself that question many times.... I think in many cases they probably try that and because of the limited nature of how most of us perceive reality, we can't hear/see them unless they make a special effort.
I also expect that there is likely so "rule" or "law" imposed on people who have have passed on that makes it so that they can only interact with us in a limited capacity, otherwise why would any father or mother ever separate from their children... My best guess is that since we seem to be reincarnating from life to life.... and from the research I've done I think we likely reincarnate with the same group of souls over and over that this rule or law is put in place so that we focus on living this life to learn the lessons we're supposed to learn. We can never move on if everyone we lost over our lifetimes kept hanging around. They are though, obviously, allowed to visit and occasionally help. It may also be that once they pass on they see this life for what it really is.... of no great consequence other than learning lessons and they see the wisdom in letting us keep our attention on that rather than distract us.... much like a parent might watch a child in a classroom from afar, only stepping in when truly needed.
Merddyn - And I took the one less traveled by And that has made all the difference