I've thought about the fluctuation thing. Say I was to misplace $1 ... I probably wouldn't notice. $100 would probably catch my eye, but is that only because my total wealth is a few orders of magnitude above that?

The question is if I commanded say, $10 billion, could I just as carelessly misplace say, $10,000 as I currently can with $1.

I think so, yeah. I noticed it when I started making more money when I got a full-time salaried job. Before I'd quickly notice a couple dollars missing from my account or I'd really rely on that $50 for gas.

Now I could get gas 3-4 times per week and I wouldn't even notice. I'd imagine if I was worth billions I could easily not notice 10, 20, 30k missing. Then again Buffet is notorious for being frugal so perhaps he would notice.

Probably depends how frugal you are. I'd expect for a lot of people it would come to carelessly misplacing $10,000. Especially in the sense of being happy to change the money in to a frivolous good that you forget about or believing you'd just left it laying around the house and will find it later.

Of course. Think of it as a percentage of your income, or wealth that you're OK with being unable to account for. Let's say that figure is 1% of your income.. so you make $50,000 per year, and somewhere $500 goes missing. No biggie.

That 1% figure is the same if you're McDonald's or Buffet, it's just that 1% of their income is a very big number. It's still only 1% though, so it's equally as unimportant to them as your 1% is to you.

Though 1% of McDonald's income pays for quite a few people to take it very seriously. (Even if McDonald's, the corporation, does not.)