From the moment he stepped foot on his local racetrack at Los Alamitos in California and heard the course commentator in action, the die was cast. His calling was to be calling the horses home.
The fact that Master Horowitz wasn't long out of short pants at the time made no difference, and by the time he was the ripe old age of 14, he'd made history as the youngest person in American racing history to commentate on a race.
While his debut performance could best be described as short and sweet, that first stint behind the microphone did nonetheless provide some lasting memories.
"It was a quarter horse race, so called because the runners compete over two furlongs or less. There was a field of eleven, the distance was 350 yards, they broke from the gates, I started talking, and it was all over in about 18 seconds."
These days, all distances come alike to the 22-year-old Californian, as anyone who was at Musselburgh last month and heard him commentate on a mile and three quarters handicap will testify.
For the time being at least, the East Lothian circuit is Horowitz's local course as he's currently putting the finishing touches to a mathematics and journalism degree at Edinburgh University. His love of racing stems from a dad who was a maths professor but who also taught a gambling class which meant horses, form, and odds, have long been a part of his life.
"There's a lot of science involved in betting which was what fascinated my father, and since I was young, I've known how to read a form book."
As well as commentating at some of the top Stateside tracks like Hollywood Park, Santa Anita, Lone Star Park, and Arlington, stints at Newbury, Bath, Chepstow and Stratford as well as Musselburgh have ensured Horowitz's dulcet tones have also been enjoyed this side of the pond.
"The whole thing is so different here than it is back home. No two courses are the same and the fields tend to be much bigger which is why I like the challenge British tracks present. For the moment, I treat it all as a hobby which I have to fit round my studies, but it's also my passion and when I graduate, I want to pursue it as a career."
Thus far, Jonathan still awaits his first stint as a Breeders' Cup commentator but he'll get some idea of what that entails this evening when he'll call them home at Monmouth Park for listeners to William Hill radio.
"It's show-business as far as I'm concerned so I know there will be people who like what I do and some who won't. That's fine.
"My approach as a commentator is that the races are the focus so you don't want the limelight to be on you. The aim is to make every race as exciting as possible but always to leave a little bit and make sure you don't go over the top.
"If you commentate on everything as if it was the Kentucky Derby, what do you do when it is the Kentucky Derby?"
As Monmouth Park makes Chester look like a galloping course, how the European challengers will fare in New Jersey tonight should make interesting viewing indeed, and if any of the raiders are to triumph, Horowitz reckons it could be Dylan Thomas.
"Monmouth is only a mile round on dirt with the turf track seven furlongs, a straight of a furlong and a half and tight turns. They say his high draw is against Excellent Art in the mile but I'd be more worried about his style of running.
"He looked to me like a horse you have to work at when winning at Ascot and if it took him so long to get going then, how's he going to manage here?
"On the other hand, the pace is going to be a lot quicker than he's used to which should help, so if Johnny Murtagh can get a good position early on, who knows?
"We call the Breeders' Cup the World Championship which I know sounds like typical American understatement, but it's as close as you can get, and with $23 million in prize money, it will be the biggest purse ever for one single sports event. The Classic is the highlight of the card and this year it will be harder to win than ever.
"Five of the field are three-year-olds and while no horse from that age group has won in seven years, this looks the strongest crop for a while.
"Twelve months ago, I really liked George Washington but his form going into the race isn't so good this time so he has it to prove. Lawyer Ron represents the older brigade and while Any Given Saturday didn't go too well in the Derby he's had some time off and seems to be peaking for the race.
"A long shot is Hard Spun who likes to race on the lead and there aren't many who want to do that, so if they let him go, he'll battle on and might prove hard to catch."
Unless I bet on him of course.
WEEKEND RACING, pages 18-19