Like most people in their lives, I've worked (and still to, if I'm being honest) in the service industry. To be specific, I went from bussing tables in a restaurant, to serving food, washing dishes, and managing at a dining center, to where I am now: Selling liquor to people at a bottle shop. If I'm being honest, it's changed my outlook on people as a whole, and to no small degree. So here is a list of things you notice and do as a result of your job. Due to my current job at a liquor store, my examples will tend to reflect that.
1. The customer always being right means they have free reign to be an asshole.
Now obviously most people that have come through wherever I've worked have been nice and polite enough, but we've all seen rude and/or argumentative customers. Working at a liquor store, you tend to see this quite a bit more than other jobs. Resisting whatever urge you have to say what's on your mind is never fun, and feeling unable to defend yourself from a particularly pissed off customer is something I wouldn't wish on my worst enemy. Actually, I probably would wish it on my worst enemy, because...
2. The customer may always be right, but they are the enemy.
Everybody's heard of Murphy's Quantum Law: Everything that can go wrong, will go wrong. Well, I present to you Sibenaller's Law: Customers will always come in five minutes before close and do the thing least convenient for you to restock/clean/etc. We service industry workers may be paid to help you, but when it's busy, or it's close to closing time, or when you break something or otherwise make a mess, we have a glaring reminder that our jobs could be much easier if, for a personal example, people would stop breaking bottles of vodka and leaving them on the shelf.
3. Some people will go to great lengths to make a fuss if a coupon for $1 off of two items doesn't work.
It goes without saying that one dollar may be worth more to one person than another, but the people who hold up the line so they can check their receipt and make sure that their seven dollar bottle of wine was purchased for six dollars, then proceed to make you do a return transaction so they can get that one dollar back are among the most annoying customers one can encounter.
4. When there's no customers around, complaining about them is therapeutic.
I mean, complaining about anything is therapeutic, anybody could tell you that. Customers are no exception. That being said, if you're not an asshole you'll avoid being the topic of someone's therapeutic sh*t-talking.
5. Working at a liquor store, I will throw the book at you if you make me angry.
North Dakota has a state law where someone has to be at least 21 years old to legally enter the building. Obviously we look the other way for infants, toddlers, and others who can't be left alone, but giving me attitude because I carded your 18 year old son and refuse to sell to you because I saw him picking out liquor, isn't going to make me want to sell to you. I don't even know you, I'm not going to get fired and a citation for Selling Alcohol to Minors for you.
6. You're used to hearing the same damn thing repeated several times a day.
"It didn't ring up, I guess it's free!" "Wow, liquor is so cheap here in the U.S., I'm surprised you're not all alcoholics!" HAHAHA WOW YOU'RE SO FUNNY OH MY GOD I'M DYING I'M ACTUALLY DYING. YOU'RE KILLING ME.
7. You can always count on someone to break something and walk away without telling anyone.
This is more relevant to retail employers than restaurants, but a time will come when somebody breaks something, and just doesn't tell anybody. They walk away and pretend they didn't see anything, leaving you to clean up the mess. It's annoying, it's frustrating, and unfortunately, it's unavoidable.
8. Coworkers can make or break your workplace experience.
Coworkers are a double edged sword. You'll have some that you know are great to work with, as they're either great at their job, or great to be around, or both. If you work exclusively with people who are terrible at their job and annoying/jerks/dumb, it's going to be a long shift.
9. At some point, you WILL question your optimism for humanity, if you haven't already.
For me, it was hearing about how somebody actually shit their pants, shook it out through the pant leg, and continued shopping, paid for their stuff, and left the store without missing a beat. We looked at the security camera footage. It happened. We have public restrooms not 100 feet from where the incident occurred. Perhaps the guy gambled on a fart, but there's no excuse regardless. I'm just glad I didn't have to clean it up.
10. Regardless of company policy, employees phones will be checked if possible.
It's bound to happen. No way around it. My generation (myself included) always has something to check on their phone. 95% of the time it's either a text from my girlfriend or fantasy football. And I wouldn't have it any other way.
11. You may find a new hobby.
This may not be applicable for more menial labor intensive jobs but depending on the job you could find a new hobby. For me, it was craft beer and the finer aspects of liquor. I can guarantee that if I hadn't been employed at a liquor store, I would not have become a bit of a beer snob, I would not currently own a $90 bottle of Scotch, and I sure has hell wouldn't be saving money to buy a kit to home brew my own beer.