"I've did the dad duty and I have had my time walking the girls to school. One of my workers knows what's required to manage the business so I'm able to fight again. I reckon I've got another 10 years in me at least."
"Boxing is a sport you need to give 100 per cent or you are only going to get hurt," O'Brien said.
He hopes to have his first comeback fight in April and will again fight in the light middleweight ranks with his former Napier Boxing Club trainer Rod Langdon as his trainer and manager. Langdon trained O'Brien during his amateur career, which began as a 14-year-old. He won 10 of his 20 amateur fights and in 2007 he won the national 69kg welterweight title. The previous year O'Brien was second in the 66kg light welterweight class at national level.
"I've only got to lose five kilograms. I'll be ready by April. There are some top fighters in that class and I'm keen to fight the best in the country," O'Brien said.
Although O'Brien hasn't fought since 2014 he has still been involved with boxing in refereeing, coaching and judging roles with the NZPBA. This has enabled him to take a close look at future opponents.
"There are three sanctioning bodies in New Zealand - the NZPBA, the NZNBF and Pro Box. I would like to collect titles from all of them," O'Brien said.
He is looking forward to daily training routines which will emable him to mix yoga sessions and a range of other exercises with his sparring sessions. The days of him turning up to do lawn mowing jobs dressed in sauna suits wearing elevation masks to simulate high-altitude training have ended.
He also used to have 2kg weights on both of his legs and arms.
"People used to think I was a muppet," he recalled with a laugh.
Future opponents of O'Brien will be fools to treat him as a muppet. He wouldn't be making a comeback if he didn't seriously rate his chances of collecting another title or two.
This will be the second comeback in his career. His last was in 2011 after a four-year spell.
Back then he lost 14kgs within a month so he could comply with Langdon's training requirements. O'Brien knows all about the sacrifices and training routines required to achieve the goals he has set for himself.
Expect this latest comeback to be more eventful than the last one.