Learning a new language will not only make you multi lingual and add another skill set to use, but also it will open a whole new world for you. For example if you learn Spanish you will not only speak that language but it will also help you explore their culture more intricately and help you understand their films and music which you might find more interesting than your previously known tastes, which you wouldn't have known otherwise if you didnt speak that language. This is just one example there are many more benefits to learning a new language.