I don't think this can be said for every job- but I know that every audition, competition, lesson, coaching, etc., is a learning experience. I sang in one competition and observed another, had two auditions and rehearsals for my production, and every one of them offered a chance to sing, listen, and learn from how things went. To be sure, not every note I sing on a daily basis is gorgeous, and when you throw in the nerves of competition or auditioning, interesting things can happen. My goal continues to be to have every performance be one I can be proud of- whether or not I win or get a role, to be able to walk away knowing I sang the best I could on that day.
I just got back from a trip to Washington, DC for some rehearsals. There are few things as nerve-wracking as having to prepare for rehearsals and not being sure if you've done enough on your own to get ready to be a fully participating member of a show. In this case, I showed up with the knowledge that the most of the other singers had already been rehearsing for two weeks. This time around, I focused my energies on just preparing myself as fully as possible- and what do you know, I was fine. I'd sung in the space before, and know several other cast members. It's nice to walk away with a greater understanding of your own skills and more confidence in them.
And to get to enjoy some spring sunshine and cherry blossoms...