My daughter-in-law uses that line on the grand-children.  Little kids do silly things even after they are instructed and warned.  Often the consequences are the only punishment necessary because they are painful enough.  "That's what you get..." when you don't listen.  Of course that is followed, in some families, by an additional litany of standard parental sayings often used in order to reinforce the point.  The proverbial, "Well duhhhhh!", may well be the coup de grace adding a slight amount of sarcastic insult to the aforementioned injury.  Jesus Christ is full of grace and truth but the conclusion of the Sermon on the Mount is a gentle reminder that if we ignore His teaching and do the things we were warned against we're going to have problems.  In fact, Jesus said there were two kinds of builders, wise ones and foolish ones.  The difference is not their I.Q., it is their obedience.  Both builders heard the truth but the wise one actually did what Jesus told them to do.  If a house was the only thing in question here it wouldn't be that big a deal but Jesus is talking about building a life!  Building a life is a big deal and if the life in question falls apart, it never falls alone; "great is the fall of it."  Jesus is always ready to rescue us but He will not always deliver us from the consequences.  The consequences for disobedience are designed to get our attention (hear, "That's what you get...").  So if a flourishing and stable life is what we are trying to build we better pay attention to the One who knows what life is about and how to live it.  Building on the rock is more than a profession, it is the active, daily obedience to the King that brings long term fruit and stability.  He is a brilliant King, will we follow Him to the life He promised?