Look, this was a shock to the system so you're going to have these moments of sadness from time to time. We all do, even the super vets that have been moved on for years. The key is to feel that emotion. Don't bottle it up or suppress it somehow but just feel it, understand where it came from, then move on. Most important thing is you don't get stuck in that place.
Personality is who the world sees, character is who you are