With the World Snooker Championship having drawn to a close at The Crucible in Sheffield, questions will again be asked about the mentality of former champion Ronnie O'Sullivan.
O'Sullivan is undoubtedly the most talented player of this or any other generation and has won the title on three occasions, but he remains a frustrating character.
His challenge this year ended in the quarter-finals, with Mark Selby putting out The Rocket 13-11, before one of O'Sullivan's customary post-match moans.
He said on this occasion: "I love the game and it's been great to me. I'll always be involved in snooker because it's in my blood, but I don't need it.
"But it's like a drug and I know I'll miss it and I'll always think 'what if?'"
Such comments have become all too common from the 2001, 2004 and 2008 world champion, who many pundits expect to take the title every year without fail.
Many of 34-year-old O'Sullivan's problems have been evident from the first moment he burst onto the scene, with his quickfire, flamboyant style of play always likely to bring inconsistencies.
However, his mental state has been the focus of attention in more recent times, with the Essex Exocet suggesting that he might quit the game after losing in the 2005 World Championship quarter-finals to Peter Ebdon - after throwing away an 8-2 lead.
The following year a semi-final loss to Graeme Dott hit the headlines after O'Sullivan appeared to tear the tip off his cue, securing a 15-minute break to repair the damage and collect his thoughts.
At the 2006 UK Championship, O'Sullivan staged one of his most high-profile meltdowns, walking out of his match against Stephen Hendry, saying he had enough when trailing 4-1.
The 2007 World Championship saw O'Sullivan at close to his best form, but in the quarter-finals he ran into eventual champion John Higgins, who was at the peak of his powers.
A year later he completed a hat-trick of Crucible successes by seeing off Ali Carter 18-8 in a one-sided final, but still O'Sullivan spoke afterwards about the possibility of giving the game up.
Even in victory, the mental side of such a gruelling game was clearly getting to the gifted O'Sullivan.
The defence of his title would end in the second round in 2009, when he lost out 13-11 to Mark Allen, while his defeat to Selby a year later now means that O'Sullivan has only won the title once in the last six years.
For any other player that would be acceptable, but for O'Sullivan it only goes to show that even his unrivalled talent cannot overcome the vagaries of the mind.