So I have this little bit of a problem with my daydreaming. I'll illustrate it with the latest example, but it's really just representative of things that happen all the time in my head. (I'm wondering if it's just because I need to engage my Ni and life these past few weeks has been uneventful.)
I moved back in with my parents this fall; my dad wants to try to go to Cuba as a last family vacation during Christmas break (my sister will be home from another university for Christmas, it's unlikely I'll be living with them next year...). The last family vacation we went away for a few years ago involved SCUBA Diving.
My Ni takes this information (the potential of going away for Christmas break) and clearly decides that I'm going to go diving, enjoying myself on a coral reef, and an 8 foot bull shark will prey after me, because I'm always the smallest diver in the group. Then when the shark tastes me and drags me for a second like a rag doll (engulfing my tank so that I only get bit across my stomach and legs), blood leaking everywhere in the salty water, he realizes I'm not tasty food, and is scared away by the hissing air tank because he punctured it.
At this point, I am bloody and he cracked a few of my ribs as well, and I can't shoot up to the surface because I'm far enough below that I'd "get bent" (the different pressure underwater changes the size of the air molecules in your circulatory system, so you have to go up very slowly and equalize or else face potentially lethal consequences).
So I had like a day of envisioning exactly how it would feel to encounter the shark, and envisioning exactly the stress involved with hearing him puncture my tank; then I envision how to react to the multitude of ways my dad and brother and fellow divers would react to the situation and figure out how to get their "octopus" (secondary breathing mouthpiece in case a fellow diver experiences problems with their breathing apparatus and you suck the same tank through different tubes). All the while, I'm training my brain to constantly blow the air that remains in my lungs out. (As soon as you stop moving air when diving, you're in huge trouble.)
I constantly do stuff like this. Most of the time it's just interpersonal interactions, but when my real life gets a little boring, this is what I'm doing in my head.
Please tell me other Ni users do this too.