"It probably took me a little bit longer to adjust than I thought it would," he said.
"I probably thought I would jump straight into it and be good at hooker. It is a lot of work, especially dealing with fatigue."
The arrival of Matt Orford last year, which prompted his positional change, led to rumors that Monaghan was to be sacked by the Eagles.
Earlier this year Monaghan signed a deal to join English Super League club Warrington and play halfback in 2008, but he denies having an ongoing problem playing with Orford.
"I've enjoyed my time here but obviously I've made the move to go back to halfback," Monaghan said.
"But I've never had a drama playing hooker and I've never had a drama playing with Ox."
A good student
Manly coach Des Hasler praised Monaghan for his ability to make the switch from halfback to hooker.
"He's a real good student of the game," said Hasler.
"He reads the game really well and prepares really well for the game."
The first-place Storm beat the Parramatta Eels 26-10 last weekend while the second-place Sea Eagles beat North Queensland 28-6 in the semifinals.
It's the second straight grand final appearance for the Storm, who lost to the Brisbane Broncos last year.
Manly hasn't been in a grand final in 10 years and despite having won six titles, have not won a championship match since 1996.
The grand final referee, his first time for the championship decider, will be Tony Archer, a 37-year-old police prosecutor.
Meanwhile, South Sydney Rabbitohs owner and actor Russell Crowe has flown to Jacksonville Florida to promote his side’s clash with English Super League side Leeds in the USA on January 26.
NRL Grand Final teams
Melbourne: Billy Slater, Steve Turner, Matt King, Israel Folau, Anthony Quinn, Greg Inglis, Cooper Cronk, Ben Cross, Cameron Smith (captain), Brett White, Clint Newton, Ryan Hoffman, Dallas Johnson. Interchange: Jeremy Smith, Matt Geyer, Michael Crocker, Jeff Lima, James Aubusson, Garret Crossman, Adam Blair, Sika Manu (four to be omitted).
Manly: Brett Stewart, Michael Robertson, Steve Bell, Steve Matai, Chris Hicks, Jamie Lyon, Matt Orford (captain), Jason King, Michael Monaghan, Brent Kite, Anthony Watmough, Glenn Stewart, Luke Williamson. Interchange: Travis Burns, Glenn Hall, Mark Bryant, Steve Menzies, Matt Ballin, Jack Afamasaga, Adam Cuthbertson (three to be omitted).