I get the feeling that this is what marrying a person from a different plane would be like, constantly
It's not something one understands. It's something one experiences.
It some times has its hazards. One of my spouse collectives some times forgets that their punctuation is so powerful that if they become emphatic it can induce insanity in a tiny mortal like myself. And if they yell... you die.
Don't even get me started about the ones that communicate by spawning whole new universes....
like of existence, ie a different realiy, not in a psychotic state, the reality exists, its just not your own.
You mean like on Fringe where Peter is actually from an alternate universe, but Olivia still loves him?
Accept the past. Live for the present. Look forward to the future. Robot Fusion
"As our island of knowledge grows, so does the shore of our ignorance." John Wheeler
"[A] scientist looking at nonscientific problems is just as dumb as the next guy." Richard Feynman
"[P]etabytes of  data is not the same thing as understanding emergent mechanisms and structures." Jim Crutchfield
I assume I have some kind of access to this person. I assume we can physically have contact of some kind.
That said, relating to them would be hard. Theoretically the upside is both of us would have a lot to show and teach each other, but at the same time I live in the world I live in, and at the end of the day having to discuss some kind of alternate plane I have virtually no frame of reference for (the same of this other person) seems difficult.
Do we begin to share a plane of existence after marriage? That's also a huge leap, learning a totally new culture, world and history from the bottom up.
I guess my answer is only if I couldn't find someone here, which I probably should be able to (I don't think I'd connect with this foreign plane person to begin with, our experiences would be too different to build a connection off of)