The £5,000bn bailout
If I were you, I wouldn't get too worked up by the Bank of England's estimate that credit-crunch losses now total £1,800bn on an assortment of financial assets, such as mortgage-backed securities and corporate bonds.
Of course it's a big number - rather bigger than the annual economic output of the UK.
But it's peanuts compared with the losses suffered over just the past month by pension funds, insurance companies, banks and all of us from the slump of more than 25% in the average value of shares listed on global stock markets (just this morning Aviva, our biggest insurer, announced that its capital surplus has fallen by £600m or 32% in less than a month).
Which is to say that the collapse in price of collateralised debt obligations - and all the investment doo-doo created by brilliant bankers that put us in our current hairy predicament - is yesterday's story.
Today's tale is that we're careering into what looks like a pretty nasty global recession, which is causing capital to be withdrawn from all but the least risky economies, markets and business - and is mullering our wealth.
The number that stood out for me in the Bank of England's latest Financial Stability Report, which I would not recommend to those of a nervous disposition, is its estimate that £5,000bn has implicitly or explicitly been made available by central banks and governments since April 2008 to support wholesale funding by banks.
That is a genuinely big number. It's equivalent to about a sixth of the total annual economic output of the whole world.
So to put it another way, we as the taxpayers of the world are funding our banks to the tune of one-sixth of everything we produce.
Blimey, if I may be so bold.
It's the measure of the extent to which the private-sector banking industry has rather let us all down.
It also tells us something about the scale of the economic downturn we're facing.
Unless we're moving into a world - heaven forefend - of semi-permanent nationalisation of our banks, the banks have to be weaned off all that taxpayer support.
That will take years, of course.
But right now, when money's tight, the best way the banks can think of reducing their dependence on taxpayers and the state is to lend less to all of us.
The less they lend to us, the less they need to borrow from elsewhere - either from taxpayers or from more conventional depositors and lenders.
Here's the catch: the less the banks lend, the less money will be available to fund companies' investment and working capital and to finance consumers' purchases of goods and houses.
Which means that the economic downturn will be all the steeper.
What does this mean for the UK?
Well forecasting the path of bank lending is more craft than science.
But the Bank of England provides some useful charts and statistics, which point in an unpleasant direction.
The one bit of good news is that the Bank of England thinks - quite rightly - that bank lending would have fallen off a cliff without the government's recently announced £400bn rescue package for British banks.
Here's the less good news. Credit from the banks is still going to be much harder to obtain for two or three years.
Well, our banks were dependent on flighty wholesale funding to the tune of £740bn at the end of June 2008, up from zero in 2001.
Most of these creditors want their money back now or in the coming two or three years - which is why the Treasury and the Bank of England on behalf of all us as taxpayers is promising to lend more than £500bn to replace the lost funds.
However, to repeat the point I've been banging on about for months, all of this will have to be repaid at some point.
Which, as I've said, puts pressure on our banks to lend less, or at least to massively reduce the rate of growth of lending.
And there's another way of looking at this very powerful force which is shrinking how much banks lend.
From the late 1990's to today, our banks increased the multiple of what they lend compared to their capital resources from 23ish to 33ish.
Or to put it another way, they thought the world was becoming a less risky place and increased by more than 40% their lending relative to the capital they hold to cover potential losses on such lending.
To state the bloomin' obvious, our banks now see the world as a pretty risky place, so they're prepared to lend much less relative to their capital.
The Bank of England thinks this could force them to reduce their assets - by cutting back on lending and dumping investments - by a sixth.
Which may seem a lot, but the Bank of England is doing its best, in trying circumstances, to look on the bright side.
It is projecting a massively reduced rate of growth for UK bank lending to customers, but it is forecasting growth (albeit of the anaemic variety).
How confident is the Bank that there'll be such growth?
It highlights a chart showing what happened to bank lending in Sweden, Norway, and Japan after comparable shocks.
In each case, the rate of bank lending didn't just slow - the overall stock of loans or credit in the system actually shank for two or three years.
If that were to happen here or globally - and it's not what the Bank of England is forecasting - we'd be coping with a very serious recession.
UPDATE, 11:58AM: It turns out I have identified an error in the Bank's Financial Stability Report. It said, on page 38, that as much as £5,000bn had been made available by governments and central banks since April to support wholesale funding of the world's banks. However the Bank now tells me it meant to say $5,000bn (dollars not pounds) - which is quite a chunky difference (as of today's exchange rate, about a third less).
That said, total taxpayer support for the global banking system isn't far off £5,000bn (yes we're back in sterling), if capital injections and toxic-asset purchases are included, together with guarantees provided in Asia and Australasia (ignored by the Bank for reasons that elude me).
So I think we can stick with £5,000bn as the total value to date of the global banking rescue, though I'm going to brand this as my estimate rather than the Bank of England's.
PS. The Bank of England is, as we speak, modifying the electronic version of its report.