*but not for the viva.
Sometimes it’s better to not know something (a news story, a headline, a particular meme that is going around) but for the viva, ignorance is definitely not bliss. You need to know things.
You need to know your work. You need to know who your examiners are and what they do. You need to know what about regulations and expectations.
You really need to know that you can’t know everything (and also don’t need to know everything).
You can do all of that. It’s not a huge task to not be ignorant for your viva. And it’s far better than missing something you need to pay attention to.