This is an eye opener. First note the age on the chart. That should shock you.

Lets analyze this in a very conservative way, neglecting not so obvious ways to cut the expenses down:
Housing: $16895, $1408/ month. I can understand that for an average house with mortgage and property taxes. etc. The question however is, for how long? Average to me indicates a life-long expense. What I mean by this is the expense has to be much higher for those with mortgages to make up for those who have paid off their houses.
Food: $6372, $531/ month. Not whole foods shoppers with a family of five for sure. But not super frugal either. One should be easily able to chop this down.
Apparel and services: $1725, $144/month. I guess this is okay for those high paid lawyers making a crapload. For me, this is &1725 in my investments every year.
Transportation: $7658, $638/' month.....of for an average driver, 55 cents per mile. Wow. this is a smoking gun. Half this and you get $3830 in the bank per year. Ride a bike and one should chop this down to just insurance on a parked used car, costing less that $50/ month, putting 7008 in the bank. every year. What a windfall.
Healthcare: $3126, $260/month. Kinda cheap actually. This is a hard one. But high deductible health plans with living a healthy lifestyle go a long way. One thing MMM has not addressed is that a lot of people spend money on health care because society says they should. A good employer will have a really cheap high deductible plan...in the tens of dollars range- or for nothing.
Entertainment: $2693, $224/ month. Another WOW. I guess internet, cable are here. But this goes to show that those things add up. Even an addict can cut this in half with no effort. $1346 in the bank with no thought...and it should be a lot more.
Insurance Pension: $5471, $456/ month. Not sure exactly what this means. Part is good, pension. Part is insurance. I have a hard time lumping pension in with insurance since one is hedging risk and the other is my future income. To me future income is totally independent of hedging risk. If even 4000 of this is retirement. Yay. Wonderful. That is awesome. Besides, putting money away is not a expenditure, it's saving.
Everything Else: $5127, $427/month. This is the slush. So make it $100/month. That leaves $3927/ year in the bank.
The awesomeness would add up to a whopping
$18006 minimum in the bank for me if I were this average based on the expenditures I noted and my savings plan. That doesn't include the unknown variables like the grocery shopping based on the scenario presented.