Goodfellas is one of the best movies ever made, but it offers education as well as entertainment. Below are nine of the most important messages you should hold on to after watching Martin Scorcese's classic for the 500th time. So read on and pay attention, you rat, you.

Everybody takes a beating sometimes.

When you learn it: After Henry's dad finds out that his son has been skipping school to make sandwiches and park cars for the gangsters, little Hank gets a few good shots with a belt.
Why it's important: If you're going to get anywhere good in life, you're going to have to piss some people off along the way. Eventually, one of those people will probably end up kicking your ass. You have to be able to take your beating and move on. Or, just do what Joe Pesci does and shoot everyone who looks at you funny.

Respect is extremely important.

When you learn it: Paully doesn't have to lift a finger against anyone and yet he has stacks of cash being hand delivered to him every day. The best kind of respect is the green kind you can use to buy stuff like prosciutto and spaghetti.
Why it's important: If you gain enough respect from those around you, eventually you'll run shit. Plus, you learn real fast when you don't give the right amount of respect to the guys that demand it. Usually, you end up in the trunk of a car with time to think about what you have done.

Never rat on your friends.

When you learn it: After Henry gets nabbed selling smokes out of the back of a car, he keeps his mouth shut in court, earning him some sincere kudos from De Niro and the rest of the pudgy, but formidable gang.
Why it's important: Whether you're a crime boss, a petty thug or even a millionaire rapper, snitching isn't cool. Even if it gets you off the hook with the cops, you're still going to come out of the joint with a bunch of angry ex-buds wanting to turn your legs into bean bags using big metal pipes.

Always keep your mouth shut.

When you learn it: It's the second rule De Niro gives Hank after he beats his charges.
Why it's important: The less everybody knows about your (and your friends') business, the better off you'll be. After the first heist at Idlewild airport, Paully gives Hank a wad of money and says, "Anybody asks you where you got it, you got it in Vegas playing craps." Since I first saw that scene, that's where I tell people I get all my money. It keeps them out of my business and helps me cover up the fact that my main source of income is sperm donation.

Fuck you, pay me.

When you learn it: When Paully takes a piece of the restaurant that Tommy has been terrorizing, he uses it as his own personal organized crime weigh station. When you owe money to a guy who doesn't care if you live or die, you better pay him on time.
Why it's important: Money runs the world. Whether it's your business or a personal loan you gave to your brother-in-law to buy a new kayak, this is the attitude with which all monetary matters should be handled. Short changed at Burger King? Fuck You, pay me. Got fired because you spent a whole day at work watching Goodfellas? Fuck you, pay me. And if someone is trying to stiff you on the money your owed, don't be afraid to go to their wig shop and strangle them with a phone cord.

Cocaine is a hell of a drug.

When you learn it: As they drag a haggard-looking Hank away to the pen, his beat-up wife hurries to dump their last bit of powder down the toilet, leaving them alone, broke and looking like they have been dead for three days.
Why it's important: Henry was living the good life before he started doing and dealing blow. Because of it, he had to rat out his friends and go into witness protection like some average asshole (you and me). He should've just stuck to bullets and ziti like the rest of his crime buddies.

Never do important business over the phone.

When you learn it: One phone call by a lazy, drug smuggling baby sitter turns the whole world upside down Paul's flat out refusal to use the phone is just another testament to his criminal genius.
Why it's important: Not only is talking on the phone less secure, but it's also way less personal than doing things in person. Anything you say carries a lot more weight when it's done face to face, especially "Fuck you, pay me."

Don't make moves on another guy's girl.

When you learn it: An extremely pissed-off Henry rolls up on some preppy jerk in his driveway and pistol whips him for getting grabby with his lady. It's one of the most satisfying moments in cinematic history.
Why it's important: If you're a guy, you should already have known this one since it's built directly into our DNA, but just in case it was unclear, Henry's masterful pistol whipping should solidify it. If you try to get too hands-on with a fine woman, expect to have to pick your teeth up off of your own driveway.

Don't use too many onions in the sauce.

When you learn it: When all of the guys are doing their time together, Vinnie is always putting too many onions in the sauce.
Why it's important: Balance is important when you're making a marinara. You don't want to overpower the other flavors with too much onion. And three small onions is too much when you're only using two cans of tomatoes. That's day one stuff.