You cannot say what a month costs
If the number in your head was assembled from the bills that arrive monthly, it is wrong and it is wrong low. A life is not billed monthly.
The man who cannot state the number is making every decision on feel, including the ones about risk.
Unexpected expenses arrive four times a year
A thing that happens four times in twelve months is not unexpected. It is a budget line that has not been named.
Tyres, deductibles, the dog, the brake job. You cannot predict the month. You can absolutely predict the year.
The tax money is in the spending account
It looks exactly like your money right up until the day it does not. Any amount held for somebody else that sits where it can be spent will eventually be spent, and the shortfall arrives with a deadline attached.
Revenue is up and nothing feels better
This is the clearest signal of a margin problem there is. More work at a thin margin makes life harder rather than easier, because every sale brings its costs with it.
One customer is a third of the income
It is fine until the day it is not, and the day it is not arrives without notice. The cost is also hidden: a man with a customer that size stops saying no to them, and what he tolerates spreads.
You have not looked in months
Avoidance takes four forms and they all look like something else: optimism with no plan, delegation without oversight, genuine busyness, and contempt for the whole subject. The last one is usually the most frightened.