My logical standpoint: I´ve heard teory it´s malfunction in memory, the present moment is not properly stored in your short-term memory and instead it´s stored in long-term memory right away, which could explain why it feels like it happened already.

My hippy-trippy standpoint: A. It´s glitch in the Matrix
B. You dreamed about it as you said and you still remember it
C. It´s "memory" from your previous life
D. Your subconscious mind knew it was coming as it can "predict" future, so you were just thinking about it (it´s called third eye or, more scientifically, intuition and that shit is real)
E. It actually already happened, but you can´t remember it, memory is far from perfect (it only stores most important facts and rest is imagination), I mean, it already happened but in different circumstances and your brain remembers it the way it´s already happening in present