The 32-year-old also recently received his MBE, an award for his services to football, at Buckingham Palace but said he would prefer not to focus on personal milestones.
"The MBE and 100th caps are special achievements on a personal level but getting to a World Cup would be huge," he told reporters.
"I don't like to rank achievements or say this is more important but it goes without saying that to play in a World Cup finals would be special as many great players have been unable to do that.
"It's not my personality to be sentimental. It's more a nice feeling for my family at the game. They can enjoy it more, but your focus automatically is on the game and you are in the zone at that point."
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Davis, who led his country to the knockout stages of Euro 2016, said the team are confident of being able to overcome the Swiss and reach next year's World Cup finals.
"It's going to be a difficult game but there's a lot of belief within the squad, and it's two games for us to get to the World Cup so we will be giving it our all," he added.
Northern Ireland visit Switzerland to play the return leg on Sunday.
(Reporting by Hardik Vyas in Bengaluru; Editing by Christian Radnedge)
