Restaurants can be some of the most stressful places to work. Especially when there's a crappy manager. You're absolutely right that it could have waited. There was no reason to intrude on your off time over that. I'm sorry you're day was ruined because of it. But, as you said it motivated you to focus on getting closer to where you really want to be. Keep on keeping on cuz you've got bigger fish to catch =p.