I couldn't agree more. When going out for my current job, I didn't have full-time UX experience. I did have some experience in the field however, and after completing some additional position-related research, I was able to speak confidently about my preferred process, the UX industry in general, and was able to walk through a usability review of reddit.com without any difficulty.
This week we've been hiring for a different position, and I've been part of the team conducting the interviews. The topic came around to when we were hiring for my position. To my surprise, I had beat out four other UX professionals with significantly more UX experience (and whom I personally probably would have hired ahead of me). My team agreed that the biggest difference between me and the other candidates was my ability to speak effectively on the subject of UX. While the other candidates had significantly more real-world experience, they were unable to articulate their preferred processes or testing methods, common issues companies in our sector faced with usability in general, or the differences between working as a UX team of one vs. being a cog in a larger UX machine.
In the end, it was my ability to communicate my thoughts and well-researched facts that won me the gig.
My advice to you would be to study up on common UX interview questions as much as possible, and to have answers prepared ahead of time for the more common questions. By rehearsing your answers and being prepared to speak on particular topics, your delivery will come with more confidence, even if you don't feel truly comfortable with your UX ability in general.