Worry is useless! The first time I read this sentence, more than 20 years ago, it made me think a lot.
At that time, living carefree I saw it as a lifestyle of a lazy person, without a job, as the greatest expression of laziness, so I had to internalize this phrase in order to understand that living carefree is a responsible life, is to take charge of what you can do and accept that there are situations that escape your own influence.
Besides, worry is a thief of energy, of peace, it is exhausting to maintain overwhelming thoughts, it does not allow you to enjoy the present, what you really have.
Another phrase that caused equal or greater impact on me is "God does not need my advice". Sometimes we pray to God and we tell him how we want him to do things. Hahaha!
And I, being an innate planner, tend to "give my programming to God" to fit my plans, which is too crazy, so when I catch myself giving my instructions to God I repeat to myself: God doesn't need my advice.
I mean it's easy for me to worry, it's like the predestined choice, like an automatic response to certain situations, particularly if they are new, if they take me out of my comfort zone, then I start with analyzing what I have control of and what I don't, because this life that is my life I don't want it to be stolen by energy thieves.