Remember Andy Murray's shocked expression at the moment of his greatest triumph? The one where a latecomer to the court couldn't have been wholly sure whether he had won or lost the US Open final?
Of course, it can't have been easy to process the sudden shift from nearly-man to grand slam champion. But that wasn't the only thing boggling Murray's mind. There was also the fact that host Mary Carillo was presenting him with a cheque for $1.9?million. Or so she claimed, anyway.
"When they say it's a cheque, there's actually nothing in there," Murray revealed last week. "It's an empty envelope. I guess it's done by wire transfer. I'm not 100 per cent sure.
"It's obviously a ridiculous amount of money," he added, looking as much overwhelmed as delighted. "I've no idea what I'll do with that. An accountant will look after it well hopefully. I guess in some ways it's a good thing that in tournaments like that you're playing for a place in history rather than for the money." Murray entrusted his mother Judy with the 'cheque' as they made their way off court and into the tunnels that wind around the bowels of Arthur Ashe Stadium. She was also carrying a bottle of champagne, which was destined to be sprayed in all directions.
Judy, the Tiger Mum of British tennis, invested so much time, energy and hard cash in the junior careers of her two sons. Now, both of them have won grand slam titles, even though Jamie's prize money of around pounds 80,000 for his mixed-doubles win at Wimbledon in 2007 falls some way short of the roughly pounds 1.2?million that Andy eventually collected.
"It's weird," the younger brother explained. "It's not something I'm thinking about when I serve for the match, but it's just such a ridiculous amount of money. It should figure [in your mind], but it really doesn't.
"It's the biggest cheque I've ever won on the tennis court by an absolute mile. I'd never have thought I would be playing for that much when I was a kid."
So what were the prizes on offer in those early days? Murray cannot quite remember the details of his first winnings, though he added: "My mum will know the answer. It would have been about pounds 100 from a Futures tournament, when I was 15 or 16." And what would he have bought with it? "I was in Barcelona then, and at weekends we would just take the bus to the local supermarket. There was a McDonald's there so we would have some food - I always go for a chicken sandwich or chicken nuggets - and then we would buy Oriole biscuits, all the bad stuff we shouldn't have been eating.
"I remember when I went over to Barcelona to start playing I always felt bad asking for spending money. Mum and dad were always like 'make sure you take enough money out.' Me and Jamie never really liked doing that, and once I started to earn my own money, I started to appreciate it a lot more. When you spend your first pay-cheque and you start being able to pay for things yourself, it's a very nice feeling."
Murray now has career earnings of $23.4?million (pounds 14.4?million) from the ATP tour alone, even before you figure in the endorsement deals. But he isn't an acquisitive character by nature; if he was, he would have long since gone into tax exile.
It's true that he became a little panicky about finding his Rado watch before Monday's presentation ceremony. But that was because - as he explained with a grin - "I forgot to put it on after the Wimbledon final." He is a man who feels his responsibilities keenly.
Today (Sunday) Murray will revisit his home town, greeting fans on a "walkabout" that will take him past the golden post box and on to Dunblane Sports Club. That was the site of the tennis courts where Judy - herself a former Scottish No?1 - first introduced him to the sport.
But don't expect any marathon rallies of the kind we saw at Flushing Meadows. Murray's next tournament commitment is not until early October, when he is due to begin the Asian swing with an appearance in Tokyo. In the meantime, he is enjoying his downtime - and a few calorific treats.
"When I'm home and away from tournaments I don't eat particularly well for a week or so," he said. "I like Feast ice-creams, I can get through three or four of them a day when I'm home. I'm not really into chips that much, and sweets hurt my teeth now - I had too many of them when I was younger.
"Ice cream is the only thing I'd eat a lot of when I'm back around the house, I can have it from midday till I go to bed."
After his latest winnings, he needn't worry about the size of his next dentist's bill.