So you want to learn a new language. How exciting! I am sure you will find that learning any new language, whether it be Thai, or French, or Italian, or Greek, opens up whole new worlds for you that were never available to you before you learned a language.
When you learn a second language, all of a sudden, you can go traveling in the country where that language is spoken, and you can converse with the natives! You can order food in restaurants in the native tongue and not get dirty looks for speaking English. You can barter with cab drivers for the best price, in their language, so that they will actually respect you! You can ask for directions if you are lost in some remote part of the country and no English speaking people are around. You can strike up random conversations with people in coffee shops. Yes, for traveling, learning a new language can give you all sorts of opportunities.
But traveling is not the only reason to learn a new language. By learning a new language, you develop your mind; you use mental muscles that would not have been otherwise used; you become a more well-rounded person.