Regardless of who you are and what you want to achieve, if you want to live a life with an end you want, you need a plan. The mission statement answers for your goals, and without one, any goals you set will be based on your changing emotional state and circumstances.
Its amazing what a difference simply changing how YOU think about others, creates happiness for you. You can achieve this too and I would suggest you take some time to think about how much you argue, and perhaps even try the route I took to quitting arguing.
As we get older, we leave why to our mental auto response. We leave our mind to manage when why is appropriate, and like a default email rule, we stop questioning whether the rules parameters are still valid. .