As somebody who varies between managing cashflow well and not-that-well ... it all depends on how much you make and the steadiness of your income.
For instance, last year I had a string of events where clients were a few months late in paying me. This created a snowball effect that took over a year to fully get rid of. During this time I was always running out of money by the end of the month, and it was always a race of whether my credit card payment[1] would get triggered before the wire transfer for my payment arrived.
Now I have enough saved up for just two months of living.
Suddenly cashflow management isn't a problem at all. If something happens, it happens, I can buffer it all out and money just isn't as big a problem. At least not for the big stuff.
It's a bit like clothes. I can manage my laundry perfectly fine. But if for some reason I don't do laundry on Saturday, I will be out of clean clothes by Tuesday.
[1] it's set up so it gets blocked if I don't pay it off in full every month