It definitely wasn't pleasant. But I wouldn't call it traumatic either.
To contextualize, I was at a Christmas Even service last night and I saw someone onstage start to tear up when the "born this day Christ the Lord" or whatever passage was being read. It took me back to my first semester when I was dealing with a lot of stress; the person I was seeing had told me her granddad was in dire health (he ended up dying), I was failing Calc and I had just learned that another one of my friends had just lost his granddad, right before I had to give a speech presentation. The Prof asked if i needed a minute, and I said no. We still did well, we got an A on it, I think.
I would probably call it nostalgia, if one can have nostalgia of a negative experience. It wasn't exactly lucid and didn't transport me into the memory like I've read about flashbacks doing.