Sigh .... do I even care to explain.... nevermind la ... u r correct. 

Hahaha ... ok la ...

Look "marked to market" is the most riskiest way to value assets and companies .... bcoz market can be wrong.
Warren Buffet talks abt intrinsic value (don ask me how to calculate this, i read his book and I'm still confuse).
So there is intrinsic value to ALL assets bcoz MARKET can experience over exuberance    or downright depression    . It's sentiment based ... fear or greed.

But we diverted from original discussion: Bill Gates is a different class and type of investor. And it's gonna be long discussion on this topic for next time. But if you read Robert Kiyosaki's book on Cashflow u'd understand. 

No lar got also. I just read here, "if for your own stay just buy at any price"
Ok, I will use different kind of asset to explain, commodities. Similar like properties, commodities also has up and down. The particular commodities I will use is silver.

There is a movement in graph last 2 year, where it looks like it will skyrocketed. The unfortunate thing is that I was buying when the graph is going up. Now, silver spots is way lower than the time where I enter silver investment.

I buy at spot RM100/oz
Today Feb 2014, silver spot is RM67. I bought 13 oz.

Do I lose money? In a way yes, my silver is priced less. But, if Im holding it, I am also holding from losing.

If in Feb 2015, silver spot soar to RM120/oz, will I have gains? In a way yes, my silver now priced more. But, if Im holding it, I am also holding from gaining.

P/S: But silver is not like gold and properties. At least gold can be "pawn"ed. You can not refinance using silver and Im not using loan to buy the silver. But it definitely show you that paper gain and lose is nothing until you transact the goods.

YES ... ppl out there are practising mark to market ... I know.... banks, hedge funds, news all talk abt CURRENT market values. They said market capitalization of a public listed companies ...etc etc.

But as an investor, don't get tricked by it. 
However, our discussion started with your comment as below
This comment doesn't make sense bcoz B.Gates and W.Buffet are different kind of investors.

Ok.
We mean that the mark to market method is not wrong but only bank or official accountancy use it. But if you are aiming to be wealthy, it is not good to use the method for your benchmark. If you want to use mark to market, then by definition my net worth is half million due to fact that I am insured for my death. It doesnt matter if Im not dead because on paper the company already promised to pay me upon death.

Does this mean Im rich? Heck no. Can I cash out? No. Similiar to own stay home. Even the value increase, it doesnt matter coz you cant sell it.

That is what Im saying all along. You only gain when you sell. It doesnt matter how many increase in price or value, as long as you are not selling, there will be no gain or profit. If the said bungalow is bought at 4.5m and i use another 0.5m for renovation, selling it off at 5m will means that there is no gain even on paper it increase 0.5m in value.

What I want to show you is that method is useful to calculate capital gain but not cashflow. To retire, it is better to aim for cashflow rather than gain.

I use this last example, if this cant explain it then It just mean that im not a good explainer:

U bought land 1 at rm20k.
The price increase to 100k. But as long as you are not selling, you are not profiting.

U bought land 2 at 35k, u add 30k loan to develop into plantation. Positive cashflow +rm500
The price fall to 25k as there are many nearby seller selling cheaply. Are u at lost?

Actually land 1 is called capital gain investment. While land 2 is your cashflow investment. Both are what properties investor are looking. Basically, land 1 is good for flipper, while land 2 is good for passive income.

But if you buy a house for own stay, you cant use the above principal unless you are willing to move out and downgrade.