…you did the work.
Not just the prep but all the work before that too.
You did the research. You wrote your thesis. You earned and achieved your way to submission.
You took time between submission and the viva to read more, check more and do more to be sure you were talented.
Ready means you’re probably still nervous but confident anyway; polished but not perfect.
Ready means you’ll go to your viva and pass.
Any PhD candidate can be ready for their viva, and that means you can be too!
When it’s time, go get ready.