I recently stumbled across a group on Reddit. This particular group is called Writing Prompts, and the topics are story suggestions, meant as practice for writers. People reply with story segments in comments.

I was alerted to one topic by a text announcement on my phone. The topic was:

 "People gain superpowers the day after meeting their soulmate. When a hot young celebrity does so the day after a meet-and-greet, they're desperate to find every person who they even just shook hands with that day."

As I got ready for work, I couldn’t stop thinking about it. As I worked on the assembly line, I couldn’t stop thinking about it. At lunch, I read some of the story segments others had posted in response, and I plotted a continuation and thought of all sorts of details.