One can imagine the novelist paraphrasing one of his aphorisms to construct this pithy observation: "It is never difficult to distinguish between a Scotsman with no Wimbledon title and a ray of sunshine."
The image of the 27-year-old tennis player as some sulky youth has thankfully been banished by a series of television documentaries and appearances on comedy shows. It was always a mystery to those observers who trudged in his wake on the tennis circuit that Murray was viewed among the wider public as dour or ungracious. In contrast, he is unfailingly polite and regularly witty.
He was, though, intense in his approach to his sport. He shares this trait with Rafael Nadal, Roger Federer and Novak Djokovic. But Murray's body language spoke loudly of internal strife. He had to battle himself and win before he could take the major prizes.
The stress on Murray was extraordinary and reduced to the cliches of Great British hope, 77-year droughts and unworthy jibes about his will and spirit. There was a physical price to be paid. Murray has spoken of the mouth ulcers that coincided with every Wimbledon championship and his hand shook violently as he prepared to serve for the title this year.
His frankness in discussing his nerves is admirable. Most prefer to indulge in the illusion that they are calm at every moment. Murray was not and is not.
However, after his best first week at Wimbledon it is possible to state with some certainty that the defending champion is both happy at and prepared for the challenge that is facing him.
"I think after winning it last year, the pressure of wanting to win definitely was finally released," he said yesterday. "I had worked very hard for a long time in order to get myself into a position where I was able to win the championship. Obviously I'm still feeling the pressure and the nerves but this year, they are completely different. I like having the nerves and I'm able to use them positively."
This positivity has been reflected in three successive, impressive victories against David Goffin, Blaz Rola and Roberto Bautista Agut. Murray has not lost a set in the championships and faces Kevin Anderson of South Africa today in the best of form and with his back secure and relatively painless after the operation in September.
His mood has also been helped by the acquisition of a new coach. Ivan Lendl was crucial to Murray's leap from being a contender to a grand slam champion. It is no coincidence that Olympic gold, the US Open championship and Wimbledon title were all achieved on Lendl's watch.
However, their conversations could be blunt, almost based on a "tough love" policy. The recruitment of Amelie Mauresmo, the 34-year-old Frenchwoman, has signalled a move to something less intense.
It would be absurd to suggest that Mauresmo has made huge changes to Murray's game within a short spell or time - or even that she would want to - but it was obvious yesterday as they practised at Aorangi Park in Wimbledon that her presence chimes with the emergence of a more relaxed Murray.
"It's great having Amelie around, she's a very calm person but also incredibly supportive, so naturally that helps me." he said. "She's also a great listener and, if I have any concerns, she'll listen to them and then we'll work through them in practice. She has been over to the house a few times but she's not living with us, I think it's quite important to try and give each other space, particularly during the grand slams as you can spend a lot of time together."
Murray, too, has remained largely unaffected by the increased fame occasioned by his Wimbledon triumph. "A lot of the players knew how big it was for a British man to win Wimbledon so they were all thrilled for me," he said. "However, as soon as we were all back on the tour, it was back down to business.
"Off the court, obviously the immediate aftermath was pretty crazy but it calmed down after a few weeks. I still get recognised a lot, though. It's safe to say I've been asked for more 'selfies' in the last 12 months than ever before."
The second week now begins with a match against Anderson, who stands 6ft 8in and serves with the sort of pace that can be unplayable on grass. Murray, who has won one and lost one in his two meetings with the world No.18, is a marvellous returner of serve but did find trouble and ultimate defeat against Andy Roddick when the American fired missiles in the semi-final of 2009.
The world No.5, though, will be confident that his all-round game will be more than enough to handle Anderson. A possible route to a second Wimbledon title could then run through Grigor Dimitrov, Djokovic and then Nadal.
Murray, of course, will not look beyond the considerable challenges posed by Anderson. He seems content to be in the moment. He is aware, though, of how far he has come.
After the demolition of Bautiusta Agut on Friday, he was at his most reflective. "When I first came on the tour, I absolutely loved it," he said. "But then obviously I had a few problems with the media. I didn't feel like I was represented fairly. I don't know, I went into my shell. I felt like I was getting criticised about not just my tennis but my hair, the way I looked, what I was saying. It was tough for me because my jump came quite quickly from being 350 in the world to playing in the slams and being in press conferences with a lot of people. It was a quick transition and I had a few problems in that early part of my career."
But what about now? "I feel like I'm a grown-up so I can handle myself fine now."
The coming of age has had its stresses but Murray has exulted in its rewards. A further dividend may yet lie in wait.