I have had a handful of experiences that can be explained rationally in no way except that the heavens were opened to me and I saw or sensed or spoke prophetically of the future or of things unknown to me - very directly and explicitly, not vaguely like a fortune teller. I'm not saying they prove the existence of God, and I'm not saying they are "visionary" in the way that most members would interpret that word - just that they proved to me that there is something outside of myself that understands and knows more than we do in the moment.
One was an amazing experience while blessing our second son as an infant (giving him a name and a blessing) that is so obvious that my oldest son now refers to it as our own Star of Bethlehem - something shining brightly as a sign that God's great work was being accomplished - something to which we can look and which we can remember as we make our own life's journeys. There was absolutely no rational reason for me to say what I said in his blessing, and I had no intention of doing so when I opened my mouth, but what I said was spot-on and prophetic of the life he has lived in the last 21 years - and uniquely so.
I have a gift in that regard that manifests itself occasionally, and there really is no way to explain it rationally. I can't control it, and there are plenty of times when I offer blessings or advice when I wish it would show up and not make me do my best all on my own. I don't understand it (really, almost at all), but it's real in a very objective way.