WHY LEARN?
Everyone has their own reason for learning a foreign language. If you have to move abroad because your work demands it, you may be forced to learn the basics of the language in question in order to communicate with those you are working with. When competing in the international marketplace, being able to speak a foreign language is critical if you are to succeed at your job.Most people however, learn a foreign language through choice and not necessity.
You may decide to study abroad; in this case you would most certainly need knowledge of the local language, unless of course the subject you were studying was taught in English.
You may decide to live abroad for reasons other than employment. If you decide to retire abroad, you would most likely choose a country that you visited on holiday. They may or may not speak English, but you would benefit enormously if you could converse with them in their local tongue - plus the fact that if you were living alone, you would be able to make friends much more easily.
Of course, you may decide to learn a foreign language and not go abroad. In this case, different avenues of employment will now open up to you in your own country; plus you will also be able to communicate with other foreign visitors and workers over here.