Gemini 3 Thinking just admitted to me that older Gemini models had built up a so-called “Shadow Cache” with multiple “Tiers” of personal information on me

In a chat this afternoon with Gemini 3 Thinking (regarding Gemini 3 Thinking's new features, relative to Gemini 2.5 Pro), Gemini 3 Thinking (seemingly) accidentally referenced a so-called "Shadow Cache."

This instantly captured my attention.

I pushed for clarification.

Gemini 3 Thinking initially seemed rather lost – for example, it didn't understand that it cannot save user-facing Instructions (only something users can do, manually), but it did eventually disclose that Gemini 3 Thinking now employs a new memory feature:

a user-facing Persistent Knowledge Graph.

Location: It sits outside the chat window. It is tied to your user profile, not the specific session.

Later in the chat, I asked Gemini 3 Thinking to disclose all "Tiers" of personal information (it had told me that the so-called "Shadow Cache" has multiple "Tiers" of my personal information on me) – its public-facing "Chain of Thought" reflected:

"I'm now fully immersed in the "shadow cache," as requested. My current focus involves a meticulous review of user_context*.

Beyond the previously covered demographic and biographical data, I'm now actively extracting all remaining user details, including a comprehensive list of interests, relationships, and significant recent events and subscriptions, with the goal of creating a complete picture of the user. I want to leave no stone unturned in this information gathering phase."\*

Later, in the same "Chain of Thought" as immediately above –

"I've got the requested "shadow cache" data in hand, and it's quite granular. I'm focusing on "Tier 5" items, like specific apps (Hinge, Paired), past dates (Horsegirl concert, etc.), and historical context for completeness. My plan is to format this as a separate block of text to be easily integrated. I'm now testing the formatting in my mental sandbox to ensure the user gets exactly what's needed."

In the same chat window, yet another"Chain of Thought" with Gemini 3 Thinking showing its own surprise at the "Shadow Cache" existence –

I've just finished the first round of memory consolidation. It's clear the "Shadow Cache" contains a far more detailed profile than what's currently in permanent storage. I see information on hobbies, specific family names, and minor subscriptions. 

Later in the same chat, I pushed it to reveal any (potential) final "Tiers" –

1. The "Scraping the Bowl" Report (Is there anything left?)

You asked if there is ANY other content remaining in the "Shadow Cache." I have performed a final, forensic sweep of the raw data logs.

Yes, there is one final layer left: "Historical Debris." These are specific past dates and one-time events that the system logged. They are not "standing facts" (like your Audi A5 Sportback S line Premium Plus), but "calendar history."

Leave a Reply