Speaking personally, Rachie, it took some time for the "knowing" to filter through to my consciousness. Sometimes we incarnated folks can be a bit heedless, myself heading that particular list!
My instinct though has always been to help others. Even as a schoolgirl I'd be the one in the class the others would come to for sympathy, or help, even while they also whispered about me being the "odd" one at the same time.
It took a while for my interest in spiritual things to develop - but it did, at last, and I moved quite quickly into the work after that.
It's different for each of us - but the "knowing" comes from the heart feelings, not the practical mind.
What about everybody else?
Angel Blessings to All