The 17-year-old thinks the world of his father and both attributes and dedicates his successes to him. Everybody likes his dad, he says, and shortly before he took on Hendry in Preston, some of his father's friends phoned to tell him how pleased they were for his dad that he was doing so well. The idyll is shattered by the knowledge that the call was made from Gartree prison, in Leicestershire, where Ronnie Snr is serving a life sentence for murdering Charlie Kray's driver in west London.
What makes Ronnie Jnr's achievements all the more remarkable is that he was just launching his professional career when his father went on trial. 'I idolise my dad more than anyone else in the world and maybe I was a bit weak last year, but I've come to terms with what has happened,' O'Sullivan said yesterday. He handled the news conference at Barry Hearn's Matchroom headquarters in Romford, on the eastern edge of Greater London, with a confidence that, like everything he does at the snooker table, belies his years.
He has had a lot to deal with in a short time but the strength of family feeling has helped him through. 'What keeps me going is the buzz that I know my dad gets when he hears that I have won,' he said. 'A lot of people thought I would crumble but I feel stronger because it's like I'm playing for two people now, not just myself.'
Ronnie Snr sees videos of tournaments, but the prison regime rules out watching matches live. 'He can ring me and he still gives me advice,' Ronnie Jnr said. 'He's had a lot of pitfalls in his life and he wants to make sure I don't make the same mistakes. When I talked to him about my win, he was over the moon but he quickly got my feet back down to earth when he said, 'That's history now. You've just got to think about the next tournament.'
History is what O'Sullivan keeps making. At 15 years 97 days, he became the youngest player to compile a maximum 147 break in competition, he won a record 38 successive professional matches last year, became the youngest to win an international tournament and scored a record 405 unanswered points in a ranking match three weeks ago.
Hendry has since taken that record back, perhaps mindful that his own place in the sport's history is fast being usurped by a likeable lad who lives at home with his 'mum in a million', Maria, neither smokes nor drinks and does not gamble. No novice but no vices.
And no shortage of confidence. If he ever appears arrogant at the table, he said, it is simply that he knows when he is the better man. He expects to be the best. 'I believe I'll be the next world champion,' he said simply, looking ahead to April.
Much of the difference between the good player and the very best, he said, is in the head, and he is sure he has the mental strength to reach the top. 'I come from good stock,' he said.
That is a measure of the faith in family values that will carry him up the motorway to Leicestershire today to show the UK Championship trophy to his dad.