No matter what your opinion is on something, there will be those out there willing to go out of their way to try and prove you wrong.
Many people will not necessarily respect an act of kindness.
If in a position of responsibility, any well thought out decision you make can and probably will be questioned by those of lesser position.
Be kind, be caring but above all be aware and alert for those willing to take advantage of your kind and caring nature.
Your bank is NOT your friend.
Your charge card company, no matter what they say, does not love you.
Beware the smiling sales person in car dealerships, television ads and magazines. They only want your money.
Have respect for the counter girl or guy in a grocery or department store. He or she is being paid very little to have to put up with rude, complaining customers who take out their hostilities on him or her.
Your city government really does not want your vote on things they wish to do, because they have already decided to do them.
Never get pissed at or argue with a police officer. He will win.
Never expect local road work to be done fast. Your city government did not hire the company for efficiency, but because they were the lowest bidder.
Be very, very careful about discussing your innermost secrets with your ‘bestest best friend’ because such friends can become enemies and blab them to everyone.
Lastly never, ever, ever expect too much understanding from people on the internet. There are those out there who live to argue, to deliberately insult you, to rip everything you say to shreds and will always have an opposing opinion.
Other than that, being an adult is cool. No one tells you when to go to bed, or what you can watch on TV, who you can hang with or that you drink too much. (Unless you’re married, that is.) 
CAREFUL! We don’t want to learn from this!(Calvin and Hobbs)