As the UK's brightest middle-distance prospect of this generation, headed into a summer which will take in a Commonwealth Games and a European Championships, to remain wholly insulated from the hubris is a near impossibility.
"We looked at playing down expectations," says her coach Andy Young. "But if you run that fast, you can't." It is only mid-May and the Glasgow University student has still to make her seasonal debut. Yet her inexorable ascent over the past two years suggests the clamour can only accelerate. With potentially two opportunities to further push herself into the limelight at Hampden, Muir has little option but to go with the flow.
Taking questions from a primary school audience yesterday to announce her presence in the field for July's Diamond League meeting in Glasgow, Muir is at once modest and self-confident as she ponders what might be accomplished in the months ahead.
Freshly returned from a trip to California, she and Young have plotted a schedule which encompasses just five races before the Games. It is deliberately light. The prospect from Perthshire is likely to race both the 800 and 1500 metres in Glasgow before going in just one at the Europeans. "'It may be that I run the trial for one but run the other in the championships," she confirms." I never make things easy. It's Andy's decision."
Young, a handy runner in his day, views it more as collaboration: both apprentices in their craft, both undertaking a rapid education. In March, in the Polish city of Sopot, her assault on the world indoor title had been mapped out, forecasts heighted by impressive form in the build-up. He told Muir it was simply another building block but the burden of expectation proved too intense. "I could see the nerves there," he recounts.
In tears afterwards, she was picked off the floor by Colin Jackson and Steve Cram, the former world champions working with the BBC's commentary team. There would, they said, be other opportunities. "Colin told me he'd made a mess of his semi-final at his first World Championships," Muir reveals. "So it was nice to know that even great athletes had done similar things. It's good to have been in that situation already. It would be different if it were 10 years down the line, my last chance. But I've done it; I move on."
America's West Coast was an ideal bolthole: three weeks of hard graft in the sun, building up stamina by scurrying up the hills and trails which encircle Los Angeles. The chilled ambience proved a surprise. "It was so relaxed out there; you could just walk on to the track and they were fine with it," Muir said. Though she had to prep for her veterinary degree exams, Young devised an itinerary which would include work, rest and play.
Friday, to her glee, was devoted to the last of those. "We went to Disneyland, Universal Studios and one other theme park; I made the most of it," she says with a grin. "The best thing about it was going on the rides, the rollercoasters. I went on a few of the world's biggest, scariest rides: my kind of fun."
Despite the adrenaline rushes on offer close to home, Young envisages a steadier journey towards the greatest highs. This week, he was researching the identikit of an Olympic champion to seek out some clues for Muir's possible trajectory. He worked out that, among Britons who have struck gold, the average age is 28. "When you think she just turned 21 only 11 days ago, she's still got a fair way to go," he says. "If you look at the last two distance medallists, Kelly Holmes and Mo Farah, they averaged 31."
Yet, as he doubtless knows, age is no barrier to the ultimate triumph. Many have been rewarded for their impatience. If Muir is good enough, she will be old enough. Should she achieve her short-term mission of breaking the two-minute barrier for 800m, and taking further steps forward in the 1500m, even Young concedes it would not be premature to go for a Commonwealth medal.
"It probably is realistic that she'll contend for a medal," he admits. Sitting nearby, his protégé is within earshot. She is wizened enough now to digest this kind of talk. "I think before I saw pressure as a negative," she confirms. "Now I see it as a positive. The only reason there is pressure is because people expect you to do well."
Sainsbury's Grand Prix tickets on sale via britishathletics.org.uk