[oh_sigh]

Would an attacker know that you're the kind of person to type in gibberish?

Also, you don't need to type gibberish. If your mothers maiden name is Jones, you can enter her maiden name as Steenberger and store that in your password manager.

[cortesoft]

An attacker wouldn't have to know you are the kind of person who puts gibberish... "oh, shoot... sometimes I make up a fake name but sometimes I put gibberish... I can't remember which I used here"