While it was his first visit as Prime Minister, Mr Key has been to Jakarta many times - when he was investment bank Merrill Lynch's Singapore-based head of foreign exchange, and when he headed its London-based global forex operation.
His visits then were to arrange the foreign exchange requirements of large merger and acquisition deals involving Indonesian companies.
Speaking to business leaders in Singapore, Mr Key easily slipped into the language of his previous career, telling them his "investment banking mates" regarded New Zealand as "a buy on the dips not a sell on the rallies".
But another off-topic intrusion into the trade mission came with reports that it was Mr Key who first approached SkyCity about a deal to build a $350 million national conference centre in exchange for more poker machines.
Mr Key disclosed his overture a year ago, but with another major earthquake in Christchurch that day and the death of a schoolmate of his son, Max, a day or two earlier, few were listening.
Mr Key maintained his usual affability when asked about the matter over and over this week, but his answers became increasingly lengthy and defensive.
He told the Singapore business audience that, like their nation, New Zealand was a country that "wanted to get things done".
The Christchurch rebuild is one of those things, and Mr Key's visit was about assuring Singaporean money men that the city, and New Zealand, was a good place to invest. Those investors included the huge sovereign wealth fund Temasek Holdings which Mr Key hopes will make a big contribution to rebuilding the city.
Meanwhile, there was somewhat envious admiration in Mr Key's voice when he praised Singapore's huge recently completed Marina Sands Casino complex after mentioning the "massive row" over the prospect of a few hundred poker machines in Auckland. It is much easier, however, for Governments to "get things done" without pesky obstacles such as functional democracy.
