"I have to think again if I actually really am the defending champion of the tournament," said Ko.
"It was a great feeling to win this event last year but it was more of a shock than anything."
As a 13-year-old, Ko came within a stroke of winning the NSW Open in 2011. She held a one shot lead over Caroline Hedwall heading into the final hole - a 118m par three - and hit her tee shot to within 5m of the hole.
Swedish golfer Hedwall responded in kind and hit her tee shot to 3m and made the birdie putt to put the pressure on the teenage star. Ko three putted for a heart-breaking loss.
"I was so close to winning in 2011 and I thought it was just luck that I got there. I was surprised to win [last year]. It was a great tournament and I was so proud to win because I wasn't able to practise as much as I liked before I left New Zealand."
The 14-year old produced a bogey-free final round of three under par 69 to run out a four shot victor. Ko broke Japanese star Ryo Ishikawa's mark of winning at 15 years, 8 months, and Australian Amy Yang's women's record of 16 years, 192 days in the Australian Ladies Masters.
She enjoys playing at the 5494m, par 72, Oatlands Golf Club. It is a course that fits her eye and rewards her consistent ball striking.
"It just suits my game really well. It's a very welcoming course. I really enjoy playing there."
Ko is looking to bounce back after she upset by Victorian Jo Charlton 2 and 1 in the third round of the Australian Amateur Championship last week in Melbourne.
The Pinehurst School student, who passed all of her 2012 exams despite being away for months of the year with her golf commitments, will be one of seven New Zealand golfers teeing up in Sydney this Friday when the event begins. In company are LET pro Cathryn Bristow, Lynnette Brooky, Caroline Bon, Emily Perry, Phillis Meti and seasoned professional Marnie McGuire who is making a comeback.
Ko knows she will be in the spotlight this week. She will once again look to upstage the likes of English legend Laura Davies, who has won 82 titles worldwide, LPGA player Sarah Kemp, Frenchwoman Gwladys Nocera, Hedwall and defending ISPS Handa NZ Women's Open champion Lindsey Wright.
"I am so honoured to play against the top pros," said Ko. "I always have fun and learn heaps. I really enjoy competing with them and I try and enjoy the moment."
If she can defend her title at the NSW Open this week then that would be a moment that will once again capture the imagination of the golfing world.