Nothing about handling money is instinctive. It is all learned, usually badly, usually from whoever happened to be in the house.
Which is worth saying, because it gets treated as a character trait — some people are just good with it, some aren't — when it behaves far more like driving. Terrifying at first, a hundred separate things to hold at once, and then one day you arrive somewhere with no memory whatever of the gear changes.
Ease is what repetition leaves behind. It sits on the far side of a long stretch of not being easy at all.
Nobody starts out fluent. The ones who look natural have been at it longer than you got to see.