Was it real? Did I just make it up?

I'm 20 years old, almost 21. Ever since I was in middle school (when I first started noticing it) sometimes I have trouble figuring out if something really happened or not. Did I think that's what happened? Did it happen in a movie and I think it happened in real life? Did it really happen?

For example: I remember going to a wedding and at the wedding, before it started we found out that one of the bridesmaids actually passed away a few hours before in a car crash. Now did that actually happen? Did I actually attend a wedding where this happened? Or did I watch a movie were a bridesmaid passes away in a car crash before the wedding? I honestly have no idea.

Does anyone else have this same problem?