Though most people with restaurant experience may not have as quixotic of memories as I do about the experience, I absolutely loved the seven months I spent at Nojo Ramen in Hayes Valley in the evenings after my day job at General Mills. Beyond beating humility into me, being a server taught me how to leverage my strengths (adaptability and on-the-fly learning) and weaknesses (attention to detail and patience) to become a better worker.
Here's how I would bullet point my takeaways:
Make Every Step Count
Your bottleneck resource is your attention and time. The obstacles between you and your destination are all time sensitive, so maximize each step and anticipate those obstacles by being prepared and constantly vigilant.
Someone Will Always Catch Your Mistake
That someone is your customer, and you'll have to admit the mistake to the kitchen and the floor manager (to cancel/add/rush an order). Don't waste time figuring out where communication broke down until after the rush, salvage the relationship and pray for at least a 10% tip.
Your Manager is Underappreciated
General managers tend to make less than the servers they manage. They are the ones that unlock the doors in the morning, turn off the lights in the evenings, and cover your ass when a you can't show up for your shift. I can guarantee your day is usually better than your manager's; stop whining.
Pick Your Slack Off Days Wisely
When the responsibilities are shared, your work ethic directly affects how much harder your coworkers work. They are your most considerate allies in the face of work, so treat them well when you feel well, because they'll be there for you when you need a break.