There are two elements to upset:
- A situation is not to my taste
- Mental attack on the person or other cause
Regarding a situation not being to my taste: either I can and should change it, in which case I do. Or I can't and/or shouldn't, in which case I adjust to it. Swift and uncomplaining adjustment is the only rational response.
Regarding the mental attack: firstly this is fruitless, and secondly I'm not entitled to judge. The solution is therefore to waive the judgement, and the basis for the anger is withdrawn. Others are as they are and are not 'meant' to be otherwise. Reality must be faced, accommodated, and where necessary worked around. Rivers are not meant to run in a straight line.