When, at around thirty-three (I'm 75 in April) I discovered that we can communicate with what many people call 'the spirits,' or deceased people. Also, that we are also in contact with other living people at a deeper level in our minds. It took me around three years to accept that this was real, and not just a figment of my imagination. When it finally came home to me that it's true (for me, anyway) I realized that we really are immortal beings; that is spiritual beings having an earthly experience. It changed my whole outlook.
Of course, I'm not alone in this. As the years go by I realize that there are a great many people who have the gift of 'channeling' or 'mediumship,' as it used to be called.
Of course, there are those who scoff and will never believe. But that's their loss.