I have asked that before and wondered what exactly the problem was. Outward things such as impatience are only symptoms of a deeper heart condition. In order to fix the symptom the problem must be found.
When I watch the pattern of my impatience I find that it is always associated with some crossing of my will. I am not the queen and I have no rights. I am to be a living sacrifice that out does my brother in showing honor! [Romans 12] Instead I have these felt needs and want all to accommodate me. Selfishness.
I do not think selfishness is the final root. Where does this selfishness stem from? Of course living as a redeemed person in a fallen body has something to do with it. My transformation is not complete. But where in my thinking does selfishness come from? I think it is pride.
Pride seeks its own. It is not kind nor is it loving. My selfishness stems from the prideful idea that people owe me something. It is this thought that I am somehow better than they and therefore deserve their homage. Much of the time my outburst come because my "peace" has been disturbed. My own plans have been interrupted. Very much wrong thinking.
So how will I change my focus? By the Word of course! Which words in the Word, that I am not sure yet.
I must pull out the root lie; I deserve to have my own way.