Lennox Lewis always said he would know when the time was right to hang up his gloves and walk away from boxing. After his performance against Vitali Klitschko on Saturday, some may feel Lewis thinks that time is upon him.
But just in case the WBC heavyweight champion's memory of those six rounds is a little sketchy, BBC Sport takes a look at the evidence of those who say he should quit.
Age
Lewis is 38 in September. Every heavyweight champion before Lewis has shown in-ring depreciation at that age.
Saturday's fight illustrated the problems that come with being Lewis' age.
Slowing reflexes, loss of timing and an inability to put together sustained periods of punching all seemed to hamper the British-born champion.
Motivation
In Memphis last summer, Lewis comprehensively defeated Mike Tyson.
That victory cemented Lewis' standing as the best of an era which included Tyson, Evander Holyfield and Riddick Bowe.
There seemed little point in Lewis continuing and he even admitted that he had trouble finding reasons to continue.
The excess weight around his waist on Saturday indicated that his desire to train, the hardest but most important part of a boxer's life, is waning.
Roy Jones Jr
Jones Jr is widely tipped to be Lewis' next opponent in an autumn showdown.
After seeing how WBC champion Lewis struggled against the ponderous Klitschko, Jones Jr must be more confident than ever. The WBA champion is significantly smaller than Lewis, but his hands and feet are twice as quick.
On Saturday's evidence, Lewis does not have the ability to spend five or six rounds running around the ring trying to catch Jones Jr.
Lewis' legacy
Few sports seem to spend as many column inches debating who was the best ever as boxing.
Lewis has never been drawn into the discussions, but he is conscious of where his name will rank when his time is over.
How history treats Lewis will depend a great deal on the image he leaves us with.
Although Saturday's performance was poor, Lewis did win.
For one of the few times in his career, the Gods smiled on Lewis - he may not be so lucky next time.
Health
In October 2002, Lewis met with Muhammad Ali who proclaimed that the current champion was indeed worthy of the tag 'The Greatest'.
Proud and respectful, Lewis would also have found it impossible not to notice how slowly those words came from Ali's mouth.
Most accept that Ali's physical state can be attributed to the numerous battles he had during the latter years of his career.
But Ali was not the first boxer to suffer for his trade and he will not be the last.
Sugar Ray Robinson, Joe Louis and Jerry Quarry are just a few examples of brave men whose lives came to tragic and premature ends because they carried on too long.
Lewis and his camp may brag about how the champion does not get hit much, but he took his share of hits on Saturday.
Some may say they should be the last punches he takes in a competitive bout.
MMIX
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Lennox Lewis pretends to be the greatest, but in reality he isn't. He is old and out of shape. I think it is time for him to retire, before Klitschko knocks him out. 