Have you ever been to Mass and not heard if the homily was speaking directly to something you were dealing with? Obviously, if you had, you would not know it, precisely because that is the point of the question. Now, realizing that simple fact (there are possibly lessons you missed in life because you were not paying attention, and you are still unaware of what you missed), how then should we live?
I am not just encouraging you to pay better attention to the homily when you go to Mass (though that is a good thing to do). I am also trying to help everyone to realize that we can come into Mass wearing spiritual "blinders" which prevent us from seeing anything other than what we want to see (and hear). Now picture this: a prideful man listens to a homily about pride and all he comes away with is the names of three people he knows needed to hear that homily.
What questions do you ask yourself after hearing a homily (even a bad one)? If you never ask how that applies to your situation, then you are not completely attentive to how God might speak to you. Here is a scary prayer to say before hearing a homily that should get you in the proper frame of mind to receive God's teaching: "Lord, please teach me what I need to hear right now, and show me where I am wrong in anything I think or do."