My Senior year of Varsity Baseball we were well into the season and nobody had homered yet.
Some of our games were played on fields where homering wasn't feasible because the fences were a mile away.
So one day we got to play an Away Game at A REAL FIELD WITH FENCES that about 320 down the lines and about 400 to CF.
Before the game I told a team mate that I had a dream about this game and that he hit a Grand Slam.
He rolled his eyes and laughed.
In the first inning I drew a walk to load the bases....my friend came up next and BOOM he hit a Grand Slam.
It was the only HR that any of us hit that year.
I never made predictions like that so it wasn't a case of "a broken clock being right twice a day".
It was 99.9% likely a psychological boost he got from my vote of confidence....but all these years later it was something I'll never forget.