''I suppose I could be ... I've never really thought much about it,'' he says.
An Otago-ite through and through, Mr Robertson has lived in the province most of his life, first in Dunedin and now in Alexandra, and admits to being ''a bit of a sport fan''.
An avid supporter of the Highlanders since the franchise was formed, Mr Robertson is also a passionate cricket fan, enjoys horse racing, supports the Warriors, watches a bit of football and golf and is keen on the Grand Slam tennis tournaments.
''Those four Sky sports channels on my TV get a bit of use, oh yes. The only thing I don't like is motorcar racing and motorbike racing, all that tearing around tracks.''
The best seat in the house for watching the big rugby game tomorrow night will be at home in front of the TV, he says, and he's quietly optimistic about the outcome.
''Our fellas have been going so well. If they play like they can do, we'll win, but it'll be a very good tussle.
''We deserve to be there, though. It's no fluke to get to this stage. They've played brilliantly this season, especially in the last game.
''They're a very good side, well-coached and doing what they're told.''
He singles out the Smiths, Ben and Aaron, as among his favourite players.
There's no whooping and hollering from Mr Robertson during the game.
''I just sit quietly and watch it. Other people are welcome to watch it here too, but I don't like if it's too noisy so it's OK if they want to watch the game and there's not too much yap-yap-yapping going on.''
Late-night finishes are fine, too.
He was unfazed by the late bedtime after the semifinal match.
''It doesn't worry me. I don't have to get up early in the morning.''
In his younger days, he played lots of sports.
''I never got that far in any of them but I had fun.''
Rugby has changed a lot over the years, he says.
''I can't keep up with all the rule changes, especially the ones about scrummaging and I can't understand some of the referee's decisions but I'm not about to argue with the ref.''
The amiable centenarian doesn't get too worked up about his team losing, either.
''Then the other team has just played better, haven't they? You can't complain about that. In fact I have no complaints about anything, really. I'd hate to get around moaning all day. It would drive people up the wall.''
Health-wise, Mr Robertson also can't complain.
''My head's fine ... my legs tip me up now and then but they're getting old, too. It's an interesting life, though, and I can't have too much more of it left.''