Much of the day included photos, security passes, lots of forms to connect MPs to the parliamentary process which included some night time reading, he said.
Checking in with Mr Muller at the end of the day, he said it was great to meet lots of new faces but he enjoyed catching up with others he had met 20 years ago when he worked for former Prime Minister Jim Bolger.
"They haven't changed much but I have, I was 20 with a head full of hair and now 45 and bald."
Mr Muller said the next two weeks would involve meetings and opportunities to get his head around Parliament and what it meant to be an MP. He was looking forward to learning the ropes and getting stuck into the job.
His wife, Michelle, farewelled him as he flew out for his first stint in Wellington yesterday.
"It's great to see him heading off," she said. "He's like a kid at Christmas."
Todd Muller
• Was most recently a senior executive at Fonterra.
• Has been a National Party member for 25 years.
• Grew up in the Bay of Plenty and worked on his family's kiwifruit orchard before becoming a senior manager at Zespri in his early 30s.
• Is 59th on the National Party list.
- Additional reporting Ruth Keber