His daughter returning to the racetrack that day last October for the first time meant far more than breaking a world record, said Aidan O'Brien.
O’Brien smashed the world record for Group One wins in a calendar year after claiming number 26 with Saxon Warrior at Doncaster in October. Ireland’s champion trainer was bettering Bobby Frankel’s long-standing record of 25 Grade 1 wins.
O'Brien was joined that day by his family, including daughter Ana, who was seriously injured in a fall when riding in a race at Killarney last July.
After avoiding paralysis, the young apprentice was returning to the track for the first time - though she may not ride publicly again.
"I wouldn't even dream or think about beating my record again. The only thing that mattered that day was that Ana was back at the racecourse for the first time," O'Brien said at Investec's launch of the Derby on Monday.
"Ana is a great help to me here, more or less acting as an assistant, and it's great that she has the interest.
"Nothing else mattered but her recovery. There's no decision (on whether she will ride again or not) - she's taking it nice and slowly."
O’Brien expects Saxon Warrior to show marked improvement from the 2000 Guineas when he runs in the Derby next month - and a shot at the St Leger in September now looks very probable.
The son of Deep Impact was a hugely impressive winner at Newmarket and, were he to follow up at Epsom at Doncaster, he would become the first horse to win the Triple Crown since Nijinsky in 1970, the year after O'Brien was born.
The trainer said: "The plan with going to Newmarket, and with the Derby in mind, we didn't want to start over seven furlongs. We thought a mile at Newmarket was going to be a lovely start-off for him. Obviously we were very happy with him.
"Everything's good so far. We could not have been happier with Saxon because there's an awful lot of improvement to come. It'll be exciting to see.
"We've always thought he was going to be a middle-distance horse, rather than Guineas horse. He's a big colt - he wears his head low. He's a good traveller and he seems balanced.
"He didn't have any problems at Newmarket with the dip. We're very happy with him. Ryan Moore will ride him as he's the number one rider and that's the way it is."
The O'Brien-trained Camelot came agonisingly close in 2012 after being beaten just three-quarters of a length in the final leg, and the Ballydoyle added: "It would be unbelievable if we ever had a horse that ever did it.
"If there's a chance we had a Triple Crown horse, this was always going to be the horse. And that's why we started him off in the Guineas. We are still alive and kicking after the first round."