Before I begin, I have to explain learning, since it seems to be a foreign subject to some. Learning is not the process of being taught, even if being taught makes learning naturally more easy than otherwise. The lessons of fast-food, both those that apply to my stated goal of real-food and life in general for the rest of you, don't come in the training period, at least not with instructions, high-lighters, and a test afterward. If I can shamelessly crib John Green:
"The test will measure whether you are informed, engaged, and productive citizen of the world, and it will take place in schools and bars and hospitals and dorm rooms and in places of worship. You will be tested on first dates, in job interviews, while watching football, and while scrolling through your Twitter feed. The test will judge your ability to think about things other than celebrity marriages, whether you'll be easily persuaded by empty political rhetoric, and whether you'll be able to place your life and your community in a broader context. The test will last your entire life, and it will be comprise of the millions of decisions that, when taken together, will make your life yours. And everything, everything, will be on it."
Okay, so most of you probably know that I am a generally explosive person. If my internet rhetoric wasn't a clear enough hint I can be a little firey, I'm relatively certain that I've actually said as much. And therein lies the first lesson of Fast Food. No matter your level within the company or the faults involved, every problem, every situation is transient. It exists no matter who is responsible for it existing and its resolution is straightforward and out of your hands. Chicken takes X minutes to deep fry correctly. A 4-oz beef patty will take so many seconds to cook, and you can toast a bun only as fast as you can toast a bun. This is not an excuse for actual laziness or inattention and it certainly doesn't remove any fault that may happen to fall upon you - but it is an escape from the stress of being faulted.
The X minutes it takes for Product A to cook have long been a particular annoyance of mine when I am waiting for something. In cooking in general, fast-food or otherwise, proper preparation is essential to serve customers in a timely fashion, and failure to be properly prepared is only compounded by the realization that everyone is waiting on you to finish Product A so that they can make Order 1. Understanding, however, that the delay is simply how that goes, alleviates a great amount of the pressure.
And, related to the same observation, the place you lay the blame in a team setting does not have any impact whatever on fixing the problem at hand, at least not in the immediate term. To keep the Fast Food theme going, if the counter staff suddenly shout back into the kitchen with, "I need an Artery Clogger Y", and your response is "No you don't, I made everything you rang in!", that doesn't change the fact that counter needs whatever they asked for. They may have dropped it, you may have missed it, it might have been given to the wrong customer or labelled improperly or whatever. The time you take to argue about why they don't have whatever they have is a waste of energy and good attitude, not to mention time, since you probably won't be making what you're missing while you're arguing about whose fault it is. Counter genuinely needs whatever they just asked you for. Send it up there. If a customer calls back and says "Hey, my asperagus was undercooked" and you're responsible for cooking the asperagus, the correct response isn't to puff out your chest and state that your asperagus is perfect and anyone who wants it more thoroughly cooked must be mental. The correct response is to overcook the damn asperagus and feel silently, silently mind you, responsible for knowing how to enjoy the vegetable properly.
No amount of prior preparation can make up for communication in the kitchen - if you find yourself in a position of preparation for another person's position, no matter how on point you think they are, encourage them to keep you posted on how much of what they have. Since you probably can't hold a dozen or more items in your head all at once, and prepare them all, and keep an eye on every order that comes in to mentally subtract from the amount you have prepared already, encourage them to tell you when they are out of chateaubriand or frisee lettuce or tennis balls or whatever. And likewise, if you are in a position where you have a prep cook, call your levels.
Please and Thank You are the equivalent of fuel additives - you get no extra speed or responsiveness from your team compared to shouting, but it runs that much the cleaner.
Similarly, nobody can multitask... unless you're playing with timers. The timer is a friend of yours and you should entertain the idea of using it. I've gone from being able to do one thing at a time to (functionally) being able to do about as many as I have timers for, just by overlapping the tasks. That'll be a keeper when I open the restaurant, though I'll have to make them something less annoying - I'm thinking open kitchen.