Adam Gemili admits that he had planned to return to football before becoming World Junior champion and running at London 2012 changed his mind.
The 20-year-old Londoner switched full-time to athletics in January 2012 after playing football at Thurrock, and Dagenham and Redbridge.
"After 2012 I was completely planning on going back to football," he said.
"It was the World Juniors and making the Olympics that made me think that maybe I can't walk away from this."
Gemili's winning time of 10.05 seconds in the 100m at the World Junior Championships in 2012 was the fastest ever by a Briton in the age grade and he narrowly missed out on a place in the London 2012 final over the same distance.
He followed up his breakthrough year with a fifth-placed finish in the 200m final at the 2013 World championship in Moscow and aims to be a serious contender at major championships this season.
"I want to make the Commonwealth Games and European Championships team," he added.
"As silly as it sounds with some of the sprinters in the world at the moment, you want to go there and be challenging for a gold medal."
He is in the second year of a sport and exercise science degree at the University in East London which he fits around his training.
Watch the full interview on Inspire: The Olympic Journey, on Sunday 11 May at 16:30 BST on BBC Two, BBC Two HD and the BBC Sport website.