Agreed......a good investor's advantage is in temperament, not in the above. Buffett is dead right about that. An obvious example is: feeling euphoric, rather than fearful, when the market plunges. This is the opposite of the typical reaction. But it's where the money is made. You don't need to have cash either, although that's nice. You can just sell dollar bills for 75c and buy other dollar bills for a 25c when stocks are washed out.
(BTW I'm kind of shocked to hear people on this board write that stocks were uninvestable in 2011, 2012. Good Lord. They were cheap, even 3 years after the 2009 washout and subsequent run-up. )
In summary, don't let macro stuff influence you. If you found a great local business you could buy for a steal, would you hesitate because of anything going on in the world today? Same with stocks.
Not saying this is easy for everyone, BTW. Maybe you have to be born with it. Buffett implied as much.