If it is people around you and know you love cat and some other information about your cat, he will put words like "cat" "2" "old" into inputs of brute force and make it becomes more easily to bruteforce your passwords.
The phrase indicated was just an example, I do not recommend that it be used, much less that it be so logical.
The point I wanted to emphasize is that for a hacker who steals hundreds of passwords, he will use automatic systems that will try to match the victim's password letter by letter. The probability of him hitting random letters is greater than a sentence.
I am not recommending this or any other type of password here. Just to point out that both types of passwords can be safe if used correctly.
Perhaps a mix of the two options could be something interesting to explore.