You are being stubborn today because someone has rubbed you the wrong way and not as a result of your response to them really being justified. It doesn't matter to you what the reasoning is behind the action on your part. Instead of changing your behavior, go with the feeling until it doesn't suit your needs anymore. It is a better learning experience to stand firm rather than cave because it is not appropriate according to what others may think.
Aries wants to be first, is a straight shooter and is confident in anything they undertake. If Aries can learn to pick the times when they are assertive, they will get things their way more often. Aries courage is admirable and others will envy them. Aries will need to learn how to channel their energy and stay away from others when that energy is out of control.
Note: Any predictions of future events are NOT guaranteed, they are meant only as possibilities.