What EXACTLY do people realise in Self-Realisation?

I asked this question in Philosophy and was advised to ask the question here on Buddhism as I may get better answers HERE. So I am pursuing Spirituality for quite some time now, I've had REALISATIONS but not the Proverbial Self-Realisation because questions remain. So was kinda wondering what is it EXACTLY that they realise. I've been told, you realise, "YOU ARE THE ONE" but it does nothing to me, no effect. So DEFINITELY IT'S NOT THE WORDS. What is it then?