"Appointing a member of the Opposition is interesting, but I'll take it. It's a unique opportunity for me."
The Speaker chairs meetings of the House and is entrusted with maintaining order throughout proceedings.
McKelvie said he clocked up two and a half hours in the chair on Tuesday, and would be back in action early on Wednesday evening.
"It always intrigued me how the Speaker managed to stay awake through all those speeches, but I've got no problem with that.
"I've got to listen very carefully to what some people say, that I ordinarily wouldn't have taken much notice of.
"You pretty much have control of what's going on. That is pretty interesting."
The ongoing anti-mandate and anti-vaccine protests outside Parliament had played a part in his first day in the job, McKelvie said.
"People need to express their view of what's going on there, and there were one or two of those yesterday during the course of events, where ordinarily there probably wouldn't have been.
"There have been quite a number of emails coming through telling me to turn the sprinklers on.
"I've told them I won't be doing that. I don't quite have the power the Speaker does."
McKelvie said hybrid sittings began in Parliament on Monday, meaning all 120 MPs could participate regardless of where they were in the country.
"You've got to be aware that someone is coming in from Northland or wherever.
"It actually worked really well, I was surprised.
"It was a historic day for Parliament. They have never operated remotely before."
His number one concern was still doing the best he could for the people of his electorate, McKelvie said.
The country needed to move quite quickly towards getting people back to "the routine of life".
"I think people are getting frustrated, and I know our businesses are very frustrated as well.
"You only have to walk into your local cafe and notice how few people are there compared to what it used to be like to see the damage that's being done.
"That's for almost all our small business outside of those essential ones."