estherh, In reality, for many people, it is hard to “try” to find the good in every situation they may come across. My only advice/input I can offer you from my experiences in such occasions, is to “let it go.” If someone takes your parking spot you were intending on using, take a deep breathe, say a little corny joke, and sing a little ditty, and drive off to look for another spot. Forget about them, and the parking space.
Bad things happen, and are going to happen, but if you are consumed by the situation, You will suffer, and not the perpetrator. All that will happen is your stress level will go up, or your day may be ruined.
It’s easier to type this on a keyboard, or say, but try it a couple times, and you will find yourself to be happier and content. Remember, there will still be days where you will obsess over a negative situation, but only look at those days as a hiccup, and not the real you.
I wish you luck!