Before you rush to destroy Liverpool keeper Karius' career, ponder the cautionary tale of Wakefield's Don Fox
What happened on Saturday night will be replayed for decades, but Don Fox will never see it.
The softly-spoken Englishman died 10 years ago, aged 72.
Don was a brilliant rugby league player who set a try-scoring record for Featherstone Rovers and helped Wakefield Trinity win their first two league championships.
Nobody, however, remembers him for that.
(At this point, it's perhaps advisable that you read the next bit from behind a sofa...)
With one minute left in the 1968 Challenge Cup Final, which was played in front of 87,000 fans at a rain-drenched Wembley, Wakefield were trailing bitter rivals Leeds 11-7.
All looked lost for Wakefield; indeed, their opponents were already hugging each other in celebration after what appeared to be a match-winning penalty.
But Don - who was having the game of his life and had already been voted winner of the Lance Todd Trophy as man of the match - had other ideas.
He quietly ordered team-mate Ray Owen to pretend he was going to restart with a high kick - and then leave the ball for Don, who totally bamboozled the Leeds players by kicking low and hard towards the right wing.
Wakefield's Ken Hirst got to the loose ball first, careering though the puddles and touching down for a sensational try under the sticks.
In those days, however, tries were only worth three points, so Don was left with the simple task of popping the ball between the posts from point-blank range and clinching a historic double.
Many of the Leeds players turned their backs - they couldn't bear to witness the inevitable. The Wakefield players, meanwhile, got ready to mob the 32-year-old who had somehow pulled off a sporting miracle on their behalf.
But Don missed it. Yes, incredibly, he missed it.
For a few milliseconds, the heaving stadium fell into eerie silence - only broken by the final whistle as distraught Don collapsed onto the waterlogged surface.
BBC stalwart Eddie Waring's commentary - "he's in tears… he's a poor lad" became almost as famous back then as the "they think it's all over; it is now" from the same stadium two years earlier.
Shortly afterwards, as Leeds paraded the trophy to their delirious and relieved fans, fellow BBC commentator David Coleman - with the devastated Don standing beside him - announced to viewers that they'd just witnessed "one of the saddest sporting stories in history". Nice one, David. So sensitive. Then: "Never mind, you're the man of the match. Congratulations..."
Don would have been forgiven for decking the tactless Coleman on live television, but his astonishing dignity at that moment has made him one of my all-time sporting heroes.
"When I was going up for my loser's medal, I wanted to jump… I thought about killing myself," he said a few years afterwards.
"I thought 'an ambulance might come and take me away from all this… just get me away...'"
Some cynics may say it's only a game, but Don never recovered from that pivotal day.
Sympathetic fans gave him a huge, warm reception on his return to Wakefield, but this broken man carried on for just one more season.
And, many times over the next 40 years, the Yorkshireman was treated for severe depression.
"I really wish it was me who'd missed," said his brother Neil, who normally did the kicking duties but sat out the final through injury.
"I was the sort of bloke who could shrug these things off, but our Don was a lot softer inside."
Leeds player Bernard Watson, speaking on the 50th anniversary of the 1968 final added: "It could have been me they were all talking about from that day onwards.
"I was the guy who was conned by Don's clever restart, the player who let Ken Hirst in for that incredibly late try.
"But because of what happened to Don, nobody - not even the Leeds fans - remember that."
Digest this cautionary tale before you join the ranks of those faceless people heaping vile online abuse on Liverpool goalkeeper Loris Karius today.
Don't forget, he's a human being - and that, no matter what happens from now on, he's going to have to carry those two horrendous Champions League final mistakes for the rest of his life.
Like Don Fox, he won't deserve what's coming his way - a career, a lifetime, defined - and, in all probability, destroyed in a few seconds.
It is a bell inside your head that you simply cannot unring.
Roberto Baggio is an all-time favourite footballer of mine but the abiding memory is seeing his famously pony-tailed Italian head droop after missing the crucial penalty in the 1994 World Cup final.
Then of course there's Gordon Smith, who famously fluffed the chance to score a late FA Cup final winner for unfashionable Brighton against Manchester United in 1983.
Like Wakefield Trinity, the Seagulls would never again get so close to immortality; their fanzine is called 'And Smith Must Score', a reference to John Motson's commentary on the Scottish striker's ignominy.
I met Smith several years ago and, unlike poor Don Fox, he has learned to look on the bright side.
I asked him if, 30-odd years later, people still bring up 'that miss'.
He replied: "Only about 40 times a day".