I think I misunderstood what a thesis defense actually is. 😭

Before starting my thesis, I thought the defense was all about proving that my research was perfect.
Now that I’m actually preparing for it, I’m starting to realize that it’s probably more about showing that I understand my work, why I made certain choices, where the limitations are, and how I would defend my decisions.
I’m still learning, though, and I’m sure there are misconceptions I haven’t even discovered yet.
For those who’ve already gone through a thesis defense, what misconceptions did you have beforehand? Is there anything else I should expect that most students don’t realize until they’re in the room?