"Parliament's a different environment with different challenges. I certainly haven't been bored."
The Mt Albert MP - who won 6033 more electorate votes than the Labour Party vote in his electorate last weekend - has emerged as a real contender for the Labour leadership after his friend David Parker withdrew.
Mr Parker describes Mr Shearer as affable, a down-to-earth bloke with integrity, who can relate to everyone.
A future Prime Minister? "I hope so," Mr Parker said.
Mr Shearer, 54 and married with two children, went to Papatoetoe High School before earning a teaching diploma and degrees from Auckland and Canterbury Universities.
He was a science teacher and then a consultant to Tainui.
At 32, he took a different path after an epiphany while throwing mango skins over the side of a truck in southern Sudan.
"These kids were fighting and running after them because they were so hungry. I thought maybe we had to take a bit more of a responsibility."
That period in his life - described as a cross between Indiana Jones and Mother Teresa - took him to a refugee camp in Somalia , work which made him the Herald's New Zealander of the Year in 1992, and an MBE in 1993.
The next year he won a Save the Children award for gallantry.
He has been a humanitarian worker in Serbia, Lebanon, Jerusalem, Afghanistan, Liberia, Sierra Leone, Rwanda, and most recently in Iraq, where he ran a large aid team.
His victory in the 2009 Mt Albert byelection got him to Parliament after failures in 1999 and 2002.
He was an adviser to Phil Goff from 2000 to 2002 when Mr Goff was Foreign Minister. But his relative inexperience is considered his greatest weakness in the contest.
"I do believe in giving people a foot up and I believe in equality of opportunity, and that's what a good humanitarian strives to do," he said.
"In circumstances of extreme pressure, the same sorts of things need to be done. You still need to build a team, focus on the objectives and then get out there and make a difference.
"Parliament is very adversarial, and all of my background has been in trying to bring people together and get them to work together.
"Accepting good ideas [regardless of where they come from] as good ideas is part of leadership," he said.
Q+A with David Shearer
Are you religious?
No
Do you believe in God?
Yes
Have you ever been in a fight?
During my school days and occasionally on the rugby field. I got sent to the sin-bin. I was jumping in the lineout and a guy kept fouling me, so I responded.
Have you ever been convicted of a crime?
No. But I was caught speeding a couple of times. I was about 7km/h or 8km/h over the limit on the highway.
What do you like to drink?
A beer or a wine. I'm not a fussy drinker.
Have you ever taken drugs?
When I was younger at parties, I had the odd joint.
Who are your heroes?
Richie McCaw, just for getting us across the line. For me the people who are real heroes are those who put the issue ahead of their own personal interests.
What are you reading?
Non-fiction books on the Middle East and New Zealand politics. Life by Keith Richards.
What are your hobbies?
Guitar-playing, surfing ("it's one place you can't take a cellphone"), gardening, classic cars, reading.
Where has Labour got it wrong?
We did not connect to voters generally, and why is a bit unclear to me. But I do think some New Zealanders believe we still look like the old Government, and that was one factor.
Is there anything the party ran on that you disagreed with?
Not fundamentally. There are some issues that sit more comfortably with you than others, and I'm not going to name them, but in general I was comfortable with the policies.
