Whenever I dream I visit myself in alternate universes. Some universes are very different from my own. The rules are different, what can and can't exist is different. One time I was running away from a minotaur like creature, in a futuristic holo-museum. The minotaur had glowing red/orange highlights and steam comming out of it's nostrils, a glowing axe dragging behind it on the floor. I was running. Sometimes I hid behind one of the pedestals that displayed something. And then I was running again.
When I woke up, I was scared. That often happens. Running away from something or someone in my dreams.
One time me and a friend, that I don't know in this universe, were trying to infiltrate and take down an organisation that was recruiting and using kids and teens for work or experimenting. Their base was in a cave that somehow had very high ceilings and grassy floor and everything. Kind of like if you replaced the sky with cave ceiling and kept the rest similar, yet still contained in itself. We were able to infiltrate the facility. In the end I was running again.
These dreams are weird and leave me unsettled. But they aren't the worst.
What is worse are the universes very close to mine. The dreams where most of the rules are the same. No weird Fantasy or Sci-Fi setting. Just my own world, but... not real.
Those worlds are frustrating, because I remember them and it takes me some time to realise it wasn't my own. I have conversations with people, that never happened, and when I bring up the topic when I see them again, people are very confused. Or I remember telling someone something personal, having an important discussion, but when I act accordingly it's wrong.
There are also the little things. In the other universe maybe I'm out of food, and I have to go grocery shopping. But I still do have food when I'm awake. I may wake up, planning on my outfit thinking it's winter, when really it's summer and wearing that would give me a heatstroke.
The frustrating part of my dreams is seldom that they are scary or confusing. It's that it takes so much energy for me to determine which of my memories actually apply to this world. I'm constantly questioning myself and doubting a lot of my experiences. Most often I just find a disruption in the flow of time, but it still takes energy. So much of it.
The issue stems from my "real" memories being very bad and blurry, to the point where I can't remember my own world that much better than my dreams. My actually memory is about as good as my dream memory, and it is incredibly exhausting and debilitating.