The one thing about a player being genuinely world-class is that, with a remove of time, they are often put up to ridiculous standards that no-one could ever have hoped to reach. None are relentlessly brilliant, even at their peak.
There are always average games, there are always off-days and - of course - there are occasionally some big mishaps.
If you were to go through the careers of all the greats, in fact, virtually every single one of them has one major blemish; one big negative.
All of Diego Maradona, Michel Platini, Roberto Baggio, Zico, Leo Messi and Cristiano Ronaldo have missed high-profile penalties. Johan Cruyff, Pele, George Best, Zinedine Zidane exploded when there was huge expectation on them, while midfielders as demanding as Roy Keane and Patrick Vieira both gave away silly passes that cost their sides key goals.
The conspicuous issue with Steven Gerrard's career, however, is that he has been guilty of so many of these same types of moments on so many big occasions.
He has missed a penalty at the 2006 World Cup, gifted away a game against France at Euro 2004 with an appalling back-pass, did the same in an effective title-decider against Chelsea in 2010 before committing what may be his most significant and symbolic slip in another crunch clash with the London club last season.
Last Sunday, then, he signed off 15 and a half years of competing against his club's biggest rivals with 38 seconds of chaos. The red card mightn't have been the way he or anyone at Liverpool wanted the captain to bow out against Manchester United, but that doesn't mean it wasn't a fitting end.
It actually fit with a lot of his career, especially since his very first sending-off came in a match of almost equal standing for the club, the Merseyside derby.
One especially brutal assessment would be that has had as many defining calamities as he has defining moments of utter brilliance.
While none of this is to downplay his status as a Liverpool legend and great talent, it is remarkable that such a high-profile player has made so many high-profile errors. It is where he really stands out from his peers at the elite end of the game, but there may also be something deeper underneath it.
With virtually all of the great names mentioned above, it was a sensational self-belief that helped maximise their talents. One former professional who played in repeat title-winning sides recently told this column that what marked out all of the best players he appeared with was "an almost delusional arrogance". They just weren't affected by what they did wrong. They kept going, in full confidence they would get it right.
With Gerrard it almost seems the opposite. It is as if he is not fortified by intense faith in himself, but instead driven by insecurity. Ken Early first pointed out (http://www.theguardian.com/football/2014/mar/13/steven-gerrard-liverpool) that so many of his motivations seem to be about fear of failure and letting people down rather chasing success and lifting himself up.
That is perhaps one reason why the list of his defining moments is so double-edged, since you could argue that mental outlook has simultaneously been the root of his greatest strengths and biggest weakness.
The feeling that he personally has to take so much responsibility means he has so regularly taken command of huge games - and you have to look no further than the 2005 Champions League final, or so many matches in that campaign - but has also led to an occasional overzealousness. Overzealousness doesn't always lend itself to accuracy or composure.
Sunday seemed such a clear example of this. Gerrard had been left frustrated on the bench, a sidelined figure watching so many of his teammates get brushed aside in midfield by their United counterparts.
So, he wanted to show them how it was done, show himself to be the man who takes control, show himself to again be the hero.
Instead, he again showed the other side of that hero complex. In so desperately seeking to stamp his authority on the game, he only ended up stamping on Ander Herrera. It was another slip.
It should not define his career, but it is impossible to deny that such moments have formed key parts of it.