The Celtic manager is convinced Griffiths has what it takes to raise his game after his £1million switch from Wolves to Parkhead.
And the former Hibs star is determined to prove he can live up to his gaffer's hype.
The 23-year-old striker said: "I am still young and willing to learn.
"I spoke to the manager and he wants me to become a better player and hopefully in three or four years I can manage to achive that.
"I have watched the Champions League nights on TV and there is no better place to play. This is where I want to be.
"The manager's a winner and that's exactly why I want to be here, and I'm really looking forward to working with him. I just can't wait to get started."
Griffiths played in two cup finals for Hibs, but was on the losing side each time.
Now he hopes to end his silverware drought by helping Celtic to bag a haul of trophies.
He told the Celtic View: "Celtic are winning trophies every season and I want to be in a winning team and hopefully we start off by winning the league.
"The chance to come to Celtic is a once-in-a-lifetime opportunity and you have to grab it with both hands.
"I have left a very good club in Wolves, but now i am coming to the biggest club in Scotland. You can't turn a chance like that down."