Everyone should, at some point in their lives, work in some sort of customer service job. Food service especially. You get a new appreciation for what actually goes on behind the scenes when you actually have to do the work that goes on behind the scenes.
I know this because I've had the jobs where I've had to be behind the scenes. I've worked in the fast food industry, I've worked in the retail industry. I no longer go in a store, pick up a folded shirt, and throw it back on the table. I no longer get frustrated when a hamburger isn't fixed as quickly as I think it should be. Customer service is much more than what you see at the register.
Food service involves so much more behind the scenes as far as cleaning and prepping the food goes. The food just doesn't make itself, and keeping up with people demanding food isn't as easy as one might think. You have to predict when people are going to come in and what they are going to want so you know how much to make. You have to get everything together and make it. You have to put it on the line, then you have to prep it for them when they order it.
Retail is a lot more than just scanning and bagging. You have to learn prices. You have to watch tags and sales. You have to fold and plan what is going to go where. You have to interact while you're doing all this, and make sure you get everything. All the stuff on the floor, that has to be prepared by employees who work their tails off too trying to make everything presentable so people can find what they're looking for, and when people come through and mess it up, someone has to go through and pick the mess up. When you pick up your eggs and decide on the other side of the store you don't need eggs after all, someone has to pick them up from where you decide to lie them down. When you finish your drink and sit it on an empty shelf, someone has to pick that up. When you leave clothes laying around a fitting room, someone has to pick that up.
People who work with the public have to have a lot of patience because the public does not have a lot of respect for them. The public doesn't respect that they have jobs they have to do, that their job is a lot more than what it appears to be, and that their messes create more work. When your trash lands on the floor, someone has to clean it up. When you need something, someone serving you gets it for you. They should be appreciated and respected. The people who know that best are the people who have been in the service industry before. Therefore, I think that everyone should, at one point in their life, work in the customer service industry in some fashion for a specific period of time, just to see what it's like, and to gain a new appreciation for what goes on behind the scenes.