Not arrogance, but just a glow from knowing you’ve done something well. Something to talk about, something to celebrate. Where do you find that in your PhD?
Explore how you could share that with others. Ask friends to listen to you talk about the best of your research. Your examiners won’t be expecting you to have monologues ready to reel off in your viva, but the more comfortable you can become talking about your work, the more confident you’ll be when you need to engage with them in the viva.
What are you a little proud of?