Spanish

When people say something I don’t like I just pretend I don’t understand. But sometimes when they talk about something I don’t care about, like a woman trying to sell me soap, I actually don’t understand. What is the purpose of learning a new language if I only hear what I want to hear and say what I want to say anyways? I should listen more and learn more with an open mind to improve at all. I wonder if this stubborn and closed way of communicating is affecting the style in which I think in Spanish. Am I becoming more closed minded? Or is it the traditional society here that thinks and talks in this way all the time?