Applied at bank for lockbox processor

I recently applied for two positions at a bank: one as a lockbox processor and the other as a payment research clerk. Both roles offered similar pay, and I had conversations with recruiters for each. Unfortunately, I received a rejection email for the payment research position, but I do have an interview lined up for the lockbox processor role. Despite not being unemployed and only casually looking for a better-paying job, I’ve been feeling quite down since the rejection. I can’t quite figure out why I’m feeling this way, especially since I’m still moving forward with the interview. Has anyone else experienced similar feelings during their job search?