Megosztott hang

Am The Asshole for quitting after my boss gave my promotion to the guy I trained? I (28F) have worked at my company for four years. For the last year, my manager had been telling me I was “next in line” for a promotion. I took on extra projects, stayed late constantly, trained new hires, basically did everything asked of me because I thought it would finally pay off. A few months ago, we hired a new guy—Mark. Nice enough, but completely inexperienced. Guess who got assigned to train him? M