The OP may have genuinely dreamed about the guy who died. I have always tried to figure out what all goes into how our dreams are what they are, and I've learned a few things. One, you are right about the mind changing shite out and making us think something happened in a way that it did not. A lot of time the mind considers these details filler information and simply places a face, or a name, onto something ambiguous. Secondly, I have tried for years to remember my dreams as soon as I wake up, mostly because I have always had very vivid, and good dreams and I am about to be 30. Once I became better at this, I could start working toward creating the right variables that my mind would dream about(i.e. people I miss, good times, etc). Unfortunately, we don't really have much control over our subconcious so at most all I could do was manipulate it in tiny ways.

More times than I can count, the dreams that had familiar faces in them were of people that had interacted in my life in some form the previous day. Most of the time it was the subtle ones. So in a way I've been able to get my dreams to where it's people I want in them and people I interacted with the previous day. That's about as far as I've come nonetheless, and most of the time I either don't care enough to think about it, so I forget, or the conditions aren't right.

tl;dl: I think dreams are a mixture of the subtleties from the prior day and memories that have had a deeper impact on our psyche over the years. Maybe the OP randomly awoke during the night, surfed FB a few minutes, and just happened to glaze over something happening to the guy. He didn't register it but his mind did. I have long since gotten over my best friend dying a week before our senior year of high school, but he is probably the only person who is always in my vivid dreams on average, even if I don't think about him at all when I am awake. Now that I think about it, it's usually raining when I see my old friend again. Thanks a lot Katrina(a month later).

This post was edited on 5/14/17 at 4:58 pm