You could probably write a Hashcat plugin to brute force that pretty easily. Something that tries groupings of keys that are adjacent to one another on qwerty keyboard layouts.
The thing is, nobody knows if you write a special character or not. They might try to brute force passwords without first. But the way more important factor is length.
When I wasnt using a password manager for password creation I just did random sentences that were not allowed to have meaning. They were quite easy to memorize because they were so absurd. Usual password check would be 3 trillion trillion years or something.