Your thesis is proof that you did the work. It’s the best summary you are able to make of years of research you’ve done.
Your thesis is a talisman to hold on to. It’s one more thing you can look to for confidence in your capability and knowledge.
Your thesis is a resource to use in the viva. Read it in preparation and annotate it to make it more helpful..
Your thesis is one book, but can mean lots of things.
What’s the most helpful story you can tell yourself about your thesis?