When you don't know the rules, you inadvertently break them. And then someone loses.
In a foreign country.
In a relationship.
In a business transaction.
Sometime the system has enough grace to forgive the loss and sometimes, the loss creates an "I will never do that again" sentiment.
Its called learning the hard way.
If you are trying something new, find someone who knows the rules and can help you.
It makes all the difference.