Once you’re on the journey, if you’ve planned, you’re prepared and you’ve got a realistic expectation, you’re likely going to get there regardless of how much you worry about it on the way.
In a very physical way, if you’re on your way back home from a holiday, you’re going to get home one way or another even if you do miss connections or flights are delayed. So no matter how much you worry about it en route, it won’t change things.
The same goes if you’re saving for financial independence, or you want to retire early. If you have your goal and your plan for getting to it, more than hoping it happens, then worrying all the way there won’t change anything. It’ll only work to ruin the journey.
Not worrying isn’t as easy as just saying it, but a realisation that it can be needless and instead focusing on planning can be an important shift in perspective.