Early in his career, rising Australian decathlon star Ash Moloney was terrified of the 400m and the 1500m.
At times he still is.
But such has been his rate of improvement, Moloney is now ranked No.3 on the alltime decathlon list for the one-lap race and has reigning Olympic champ Ashton Eaton's mark of 45.00 seconds firmly in his sights.
A spot on the medal podium in Tokyo isn't out of the question either.
The 21-year-old Moloney and his training partner Cedric Dubler, 26, both locked in their spots in the 24-man decathlon field for the Tokyo Olympics with a one-two finish at the national trials in Sydney.
Moloney, the 2018 junior world champion, claimed the victory with 8284 points having won six of the 10 events, while Rio Olympian Dubler was 109 points adrift in second place.
Their close relationship has inevitably evolved since Moloney first joined coach Eric Brown's squad as a 15-year-old high jumper.
"If you'd asked me a few years ago I would have said I'm a bit of a mentor for him," said Dubler.
"Now that he has started whupping me on the track I'd said we have more of a rivalry, but it's very friendly.
"A lot of banter gets thrown around and it motivates us to step up the plate."
Moloney claimed that Brown pretty much had to bribe his mother to get him to switch from the jumping events to the unforgiving discipline of decathlon as a teenager.
"It was a weird thing because I was petrified of the 400 and the 1500, absolutely petrified and I still am," he said..
"But you come out of the decathlon and you actually enjoy the feeling of finishing it.
"It's an achievement every time.
"It's a love-hate relationship; when you get a PB you love it.
"But when you don't get a PB or you pushed a little too hard too early it can suck."
American Eaton won the gold medal at the Rio Olympics with a formidable tally of 8893 points, while 8666 was good enough to secure the bronze for Canadian Damian Warner.
That's not all that far from Moloney's national record of 8492 points, while Dubler could also be in contention.
"(Success for me in Tokyo) would be one or more points above Ash," joked Dubler.
"The plan for me is to go and execute my perfect competition, to make sure all the events are together to get the score that I'm chasing.
"If we hit those scores that we're chasing around 8500 that should be getting close to the medals."