His target is gold in Lithuania in 10 weeks' time.
O'Leary (17), a member of the Otago Rowing Club, leaves Dunedin on Saturday to train with the New Zealand junior quadruple sculls at Lake Karapiro.
He competes in the junior world championships at Hamburg in Germany from August 6-10 and in the single sculls at the Youth Olympics in Nanjing, China, from August 16 to 28.
''My goal is definitely the gold medal but nothing is ever guaranteed,'' he said.
''Nothing is ever set in stone, especially at world champs. It will take a lot of hard work to get there.''
O'Leary grew in confidence as he prepared for last year's junior world championships in Lithuania.
''The big thing was to get a belief in myself that we gained as a crew,'' he said.
''At the start of the campaign we had no idea that we could get that close.
''We built up the little things at each training session and by the time we reached the regatta we had a lot of faith and belief in each other and believed that we could do it.''
O'Leary was in the bow seat in Lithuania and proved last year that he has the temperament to lift his performance on the big occasion.
''It is a lot higher level than your standard school and club regatta,''he said.
''It is a big level for us but it is only the start of the journey for me.''
O'Leary usually gets nervous before competing in single sculls.
''Last year I wasn't nervous,'' he said.
''I was quite relaxed and confident that we would go out there and give it the best race we could.
''Having the crew around me was such an awesome experience that I'd never had before and that helped a lot.''
The championships in Lithuania was the first step on the journey for O'Leary toward his Olympic goal.
His efforts impressed the rowing scouts and he was offered a rowing scholarship to the Ivy League University of Harvard in the United States.
''That was an option,'' he said.
''But my heart is here because I think it provides the best opportunity for my rowing.''
O'Leary has worked hard under the direction of his Otago Rowing Club coach, John Parnell, who has produced three internationals over the past five years.
The others are Zoe McBride and Bryce Abernethy.
Hannah Duggan has represented New Zealand Universities.
''I think they will do very well,'' Parnell said.
''It is a very good sculling crew and has the potential to win gold.''
The coach of the New Zealand crew is Bruce Jones, who was cox in the New Zealand eight that competed in Australia in 1965.
Parnell's father, Wally Parnell, was coach of that New Zealand crew.
