Irritability is as terrible as it is common. Irritability is a sin which betrays a lack of wisdom, love, and patience. There could not be a more apt way of describing what patience really is. Indeed we count them blessed who endure. Our impatience is often the result of simple tiredness.
Impatience usually comes down to a problem of self-control.
The person who lashes out in exasperation is out of control. The patient person is able to restrain himself. The critical factor is control of whatever annoyance there may be. We often lose patience with people who do not quickly respond to our advice. If you don't hurry up and snap out of it, then I don't have time to fool with you.