"I bet the door puts a lot of similar-but-different worlds next to each other, for whatever reason it picks where it goes."

"Next-to-each-other-ness doesn't seem like a concept that's being used."

"Ah, no, weird turn of phrase. I meant how we're both here at the same time."

"Bar seems to think that's less to do with how similar our worlds are and more to do with how much we'd have to say to each other but she doesn't control the door so she's not sure."

"That does make a lot of sense. So, does this mean you're done with the encyclopedia-quizzing for now?"

"I'll probably still stop to look things up. What's it like when you're newly magic?"

"It's... You have new knowledge in the back of your head, sometimes new senses. At first, it's almost like your magic has a mind of its own, urging you to use it, to grow and flourish. That goes away after a while. You start off very weak, comparatively, and a few weeks of practicing on your own usually sends you to a more baseline level and gives you a couple of unique spells."

"Senses like -?"

"If it happens to fit whatever theme you get - which tend to suit your personality, but you don't get to pick - you might suddenly get an accurate internal clock, or know where any nearby fires are, or have a suddenly more acute awareness of wind's direction and speed."

"What's being urged to use the magic like?"

"It's like having a new toy or game you really want to try out in the back of your head. Thoughts about magic are a little more special. Little thrills when you do something interesting with magic or accomplish a small goal you set, feeling stale for lack of a better word if you don't use magic at all for a while. I hear lots of people mistake the whole thing for just being naturally excited about magic, about all the things they can now do, but there was this big study and the pushing is there, just kind of subtle."

"One study? Did it replicate?"

"Uh, ask Bar?"

There have been a few different studies on this matter, mostly relying on surveys since spirit bearer 'biology' doesn't cooperate with MRIs and other medical tech very well. At least four separate studies on three continents have found the same result. There are some case studies of people who personify their magic - as a playful puppy, as divine guidance, as their old imaginary friend, etc.

- why doesn't medical tech work?

Spirit Bearer bodies are made of magic! Is the going theory. The aggressive regeneration messes up things like blood tests. MRIs are murky and staticky. X-rays come out hopelessly muddled. The less invasive it is the more it seems to work, though - those electrode patches that go on skin work okay, for example. Ultrasounds work.

How does regen mess up investigation of blood outside the body? What's invasive about an MRI?

The blood disappears soon after it's taken. Very rapid attempts to test gave results that indicated it was plain water. What's so objectionable about an MRI to the magical body is an object of active medical debate.

Incidentally, children of Spirit Bearers (any combination of genders involved that's been successful) come out as completely mundane humans, and the various genetic and physical disorders infants tend to suffer from are completely unheard of in same.

- combination of genders?

Magic father and normal mother, vice versa, both magical, and a few inconsistent edge cases enabled by more magic - but apparently magical folks' fertility is super low, comparatively.

Oh, that kind of combination of gender. Why the low fertility?

Who knows? Hypotheses: Magic gametes are just as ephemeral as magic blood, fertilizations that would have resulted in some kind of disorder are rejected, it's already a compromise for children to be possible at all given their similar nature to monsters, genies, and spirits...

Those don't run around making little demimagicthings, right?

No - though genies have been known to try, no demi-magic-things are known to exist.

Try as in they don't know they can't?

Try as in have sex with people, animals, or things sometimes, and say they want children sometimes. Only very occasionally for both.