Explaining your life to an llm, then having it generate permutations of passwords to try does sound like it would work a decent percentage of the time.

A large percentage of passwords aren't a random string of characters but a memorable word + memorable number. There's existing projects that basically do the same, and 3.5 trillion doesn't really make it clear if one of those wouldn't have worked as well, but I can see it having an above random chance to guess a password.

The idea that someone (the NSA?) is training models on all of our collected info, and using that to predict all of our hidden information, is horrifying.

The best time to start using a password manager was 10 years ago. The second best time is now.