Certain & Right
Do you feel that you need to be right in your viva? Do you need to have an answer for everything? The right answer?
I think that would feel like a lot of pressure. Needing to be right might also remove a lot of other opinions, opportunities and perspectives from a discussion.
Perhaps it’s better to strive for certainty. Take time in the viva to put your thoughts in order so that you are careful and certain in what you’re saying.
It’s far better to be clear in your responses than push to be right about everything.