It helps me think. Really. It helps to hear what is being said in a way that mentally saying it doesn’t do. We all process information differently and clearly, you do fine listening to your own thoughts, but some of us need to say and hear things. If, for instance, I’m trying to learn some Czech, I can mentally say, “Pivo – ****, **** – Pivo” all I want, but if I actually say (and hear), “**** is Pivo. Pivo, prosim!” I will remember it much, much better. Of course, this is true with many things—not just learning language. It is, in point of fact, not rude to talk to yourself. Awkward? Yes. Rude? No. Similarly, it is not pointless. You actually process the information differently if you say it and hear it instead of just thinking it.