Mems

A MEM is a type of currency traded in the Convergence.
 A MEM Is the most common form of external memory in the Convergence and largely what you'll encounter if you choose to engage with the Convergence Exchange. While MEMs can vary in size, duration, and emotional content, they are designated 1/3 of a full memory.
-Guide to Convergence 
Following the events of Convergence, the citizens of the new hybrid-world established a form of currency based on sharing memories of their home worlds. Mems are stored in Oss Crystals.
The citizens of Convergence are frequently rocked by Memory Storms, a natural disaster which causes people's Mems to be ripped from them and strewn throughout Convergence.
"Memmy" is the mascot of the currency.
See Known mems at Convergence Station for a full list.