YOU have to wonder how these fallacies come into being.
A festering misconception had grown around Hannah Miley that she was past her best, her star petering out, on the brink of her dotage after a decade of senior racing. At the rare old age of 24, she came within half-a-second of setting a new lifetime best last night and proved once more that her racer's kick is up there with the great champions of Scottish sport.
Two Olympics have come and gone without her making the greatest of all podiums. That is the stick with which she is beaten, and perhaps beats herself, but the irrepressible Inverurie woman is certainly not past it, and this victory confirmed that once and for all in her own head.
When she became Commonwealth champion four years ago it was a breakthrough - her first major long-course gold medal. European glory followed and then a World Short-Course title. But this one, wrought from the grasp of a strong rival in a race of epic tension, looked for all the world like a career highlight.
Apparently, though, all it has done is relight the flame. After breathlessly and tearfully embracing her dad and coach Patrick, her mother Carmel and younger brothers Alastair and Joseph, she found herself talking about a new era of competition.
"London prepared me very well for this moment, the home crowd and making the most of it and using it. In those two years I've learned a lot and matured a lot more. There's always something else you can learn at the age of 24 in swimming. I'm forever learning.
"A lot of my old rivals are making a comeback, the 1989-90 era, and it's not just a young person's sport any more, it's anybody's game - if you've got the heart and soul to fight for it."
Miley's performance was right up there with her best. The time (4min 31.76sec, the second-fastest in the world this year) apart, she had to come from behind at the halfway stage after Willmott, a younger swimmer from Middlesbrough with a noticeable height advantage, established a one-second lead.
Miley was not about to let a second come between her and what might be regarded as a crowning glory. She was still behind after the third 100m, Willmott having her held her breaststroke at bay, but then came the freestyle laps and Miley's experience - and dogged refusal to lose - kicked in.
"It just kind of came all together, the sacrifices I have made and my family have made. I've not been able to see my boyfriend since the end of December. It's been very, very tough on everybody not just me, so I guess the tears were just a sigh of relief for my whole family," she said.
It had been a terrific morning session. Miley had already beaten the time with which she won gold in Delhi four years ago, only to rewrite it by another six or seven seconds when it mattered most. There is a science behind her survivor instinct.
This was Miley's moment and Robbie Renwick enjoyed it, though he did not enjoy the 400m freestyle final. Stephen Milne and Daniel Wallace had set big new PBs in the heats but none of the trio had enough left to interfere with the plans of Canadian winner Ryan Cochrane and the victim of his kick, Australia's David McKeon.
Renwick defends his 200m title today and he admitted that fierce looming examination had prevented him going all-out in the 400m. Wallace finished highest of the trio in fifth, but Renwick's mind was already elsewhere.
"Watching Hannah defend her title has given me inspiration. I loved watching her in the call room there," he said. "We had to stay focused on our own race, so it's not as if we could be up on the seats cheering. I think we'll all take inspiration from that."
At the end of an opening day when historic Commonwealth Games standards were rewritten so freely, it was fitting that the 200m breaststroke, which has borne so much fruit for Scottish swimmers over the years, should close the show. And it has to go down as the greatest race between two Scots in a pool.
Christian Sprenger, the veteran Australian in lane eight, acted as a celebrity pacemaker. At the 100m mark he was under world-record pace but then Jamieson caught him, and instantaneously Murdoch was on his shoulder.
This unprepossessing 20-year-old, born in Alexandria and raised in Balfron who was never even rated at senior level until he was 17, stole a march on the local favourite and refused to relent. His winning time, 2:07.30, was a British record thieved from under the Olympic silver medallist's nose. Scotland has not one but two breaststroke swimmers of the very highest calibre.
Bring on Rio. For Murdoch, bring on the 100m tomorrow.
"It's just something I can't explain, that last 50m, having so many people cheering me on. It was something I'll remember for the rest of my life," he said, adding with a nod to the silver medallist: "He's still an idol in my eye."