You become careful who you associate with
You find out the truth behind "you are who you associate with" when you travel overseas. Always remember you are the average of the people you interact with on a daily basis. If someone is bad for you, then ignore them and cut them off. You are who you talk to and build relationships with.
You realize people have good and bad traits
The world is full of all different types of people: good, bad, beautiful, ugly, etc. Nobody is perfect and we all have flaws. No matter what language you speak, you can minimize your bad traits and maximize your positiive ones.
Western Society isn't Perfect
Western society is great for business and education but there are other social problems that you must avoid. No matter how good western society is doing, there will be flaws.
You learn from other people's mistakes
Staying in your comfort zone doesn't allow you to learn from other people's mistakes. Being around a different culture makes your poor habits obvious. You need to stop bad habits and pick up good ones.
You become a stronger person
International travel has risks. Many people do not make it back home in one piece. Living overseas tests your strength to survive in a foreign environment. You become harder to destroy.