"Getting this opportunity, I feel like a young kid with a dream again, to play in the NRL.
"I was looking down the path of trying to get work and when I started scaffolding, I definitely didn't want to be doing that.
"Then I worked for my father in law as a brickies labourer and I definitely didn't want to be doing that.
"That made me want to get back into playing football again and to get the chance to pursue that again, I appreciate it more than anything."
After debuting for the Warriors during the 2009 season, Locke went on to play eight tests for the Kiwis but found himself on the outer at the Auckland club following the arrival of England international Sam Tomkins in 2014.
A shift to England saw him link with Salford but the deal went sour with Locke parting ways with the Red Devils midway through 2015 following a pay dispute.
He joined Wakefield but injuries limited him to just five appearances in three months and he was eventually released from his contract after being suspended following a car crash involving former Parramatta playmaker Tim Smith.
He underwent shoulder surgery this year before signing to play for the Greater Sydney Rams in Australia's National Rugby Championship but did not see any game time.
His troubled past saw him struggle to attract any interest from other NRL clubs before Barrett offered him a chance at Manly.
"He's an awesome bloke and he's always been really supportive of me," he said.
"With clubs, they never doubted my ability, it was more my off-field stuff.
"With the past that I've had, it wasn't the greatest and it made a lot of things difficult for me.
"Now I've been given the opportunity and I've had a long think about how I'm not going to be in this position again."
Locke faces an uphill battle to oust young gun Tom Trbojevic from the Sea Eagles No1 jersey but is focused on proving his worth to the Manly coaching staff and his new teammates.
"It is my last shot and that's how I take it.
"My ultimate goal is being out on the field week to week and that's a massive goal to achieve with Tom Trbojevic at the back and he played some good footy this year.
"I've just got to keep working hard and keep plugging away and I can't think that far ahead."