While researching #plurality stuff I came across the concept of "headspace" which I'd seen described, but never named in some plural fiction. I didn't realize it was a real thing, because my inner world has always been talking with myself in a void of nothingness. Once I knew what to look for it was impressive to read about other people's.
Headspace
A headspace (also known as inner world or wonderland) is a place that members of a system can visit or inhabit, where they can talk to other headmates. Not every system has one, but many do. It is also not unique to systems. Singlets may have a headspace as well. In addition, a headspace is not necessarily...

