I think nearly all of the world's problems wouldn't exist in the first place if everyone was able to perfectly communicate and interpret each other's thoughts and feelings accurately. Language barriers, misinterpretations, presupposed narratives, a lacking vocabulary, all contribute to most, if not all conflicts. Just look at almost any movie (especially romantic movies) - most of the problems in them could easily have been prevented if people just talked to each other properly.
I think good communication skills are often the determining factor of whether a relationship is doomed to fail or not. I've seen firsthand how relationships slowly deteriorate because of a deficiency in communication skills. That includes some of my own relationships with my Spanish speaking family. Although I do speak Spanish, my vocabulary is not complex enough for me to be able to properly say what I mean.
Not being able to speak my mind is one of my biggest fears. To me, it is a personal hell to live a life where you're never fully understood. This is why I admire authors and public speakers. They are able to express themselves the way that they want to, or at least to a better degree than the average person. Getting to that level is something I strive to do. This is a huge reason for why I'm blogging. Practice makes perfect.