1. Never Admit Fault
   It's honorable to own up to your mistakes, but the honor code is dead.
It's easier to push the mistake into someone else's hands and walk away than it is to deal with the consequences.
Even if your hand is caught in the cookie jar, blame it on misinformation.
Admitting fault may give you reason to hold your head up, but it still means you have someone to answer to. It's easier to recover from a bruised ego than a broken nose or wallet.

2. Cover your Ass
   Always have a reason for what you're doing. The reason can be legit or not, as long as you sell it.
Have an alibi. It doesn't matter what the situation is; at any point you may need someone to backup what you're selling.

3. Learn to Fake a Smile
   No one is going to give you a minute of their time if what you have to say seems anything but legitimately happy or uplifting.
If you can't sell yourself as happy; no one will enjoy being around you. You may be the absolute best at what you do, but performance is perceived as the energy you give off while doing it. Good people have fallen far, simply because they did not have confidence in their actions.

4. Never Throw the First Punch
   The one who starts a fight is the one who will end up in handcuffs.
You can say anything, insult anyone, even spit in your enemy's face... But whatever you do; do not touch them. Take the first hit, then do your worst. When it's all over; be the victim and cover your ass.

5. Observe
   Notice everything. You never know what information could come in handy.
Watch people's interaction; focus on the smallest details and mentally note them. If there's no people around; bird watch. Try to identify species as they fly overhead, even at a distance you can tell what species a bird is by the way it flaps its wings. Practice every day until it becomes second nature.

6. Blend in
   If a situation is out of your control; keep your head down and do what everyone else is doing.
Don't risk getting caught in the crossfire, don't compromise your own security if the risk is too high.

These aren't lessons for getting ahead in life, they're lessons in staying in control of whatever situation your in.
These are the lessons that were drilled into my head back when I worked in the security industry. They may not be the most inspirational, nor the most honorable. But they work.
The lessons don't just apply to security, they can apply to any situation. School, work, if you're a hostage...