Every candidate needs to survive their viva, and given what is needed at the viva, every candidate can survive their viva.
You can want and have more though.
- You can survive and enjoy your viva. It could even be fun!
- You can survive your viva and learn from it. Pick up interesting ideas from your examiners or discovering something for yourself.
- You can survive and thrive in the viva. Grow through it, be re-energised.
You can do more than survive, but survival could be enough. It may be all you get. As with so much about the viva, and life in general, it comes down to how you approach it. If you want to enjoy your viva, what could you do to tilt things in that direction? If you want to learn, what questions might you need to ask? If you want to thrive, how might you need to prepare?
Surviving is the default; is it enough for you?