If you're going into the world of business, then you have to get used to failure. Whether its a small failure or a huge failure, knowing how to deal with it will make you a better entrepreneur.
Billionaire business man, Donald Trump always tells young entrepreneurs this:
"Fail then come back stronger: Deal with failure, by getting back up, and changing strategy. Some people are married to the idea that their way is the only way, and refuse to alter it in any way. They do this to their peril. Times change, people change, and so must some strategies."