In 1939, he rode a pony called Gamble from Tarras to Mount Barker, and then into Wanaka on the morning of the show.
He did not win a ribbon, but his mate did, he said, laughing.
Mr Gibson's father was on the committee that organised the very first show and meetings were held to establish where it would be held.
The likes of Hawea Flat and Cromwell were suggested but it was Wanaka - or Pembroke as it was then known - that won out.
Shows were in the family's "blood'' and he recalled starting showing sheep in Christchurch in 1956.
Mr Gibson has travelled to A&P shows all over the world and Wanaka, he believed, was the most picturesque showgrounds around.
In the early years, it was very primitive - by today's standards - with a ring and activities that included steer riding, despite there being no proper fencing to keep them in.
Robbie has carried on the family involvement and is a past president.
Malvern Downs had a team of merinos entered in the show last weekend and they were looking "all right'', he said.
He still maintained a keen interest in the stud and knew all the sheep and their sires.