The contract kept him in Dublin until the end of the 2007 World Cup but on Wednesday he gave Irish rugby a huge lift by extending the length of the deal until 2011.
The 27-year-old admits he gave serious consideration to moving abroad before the arrival of coach Michael Cheika at Leinster and the IRFU's approach to player welfare convinced him to stay.
"The contract was kept quiet because it was important we kept negotiations to ourselves this time around and didn't create a hullabaloo," he said.
"The way it worked out was very amicable. Both parties were very happy with the situation. It's great I can put that behind me and look forward to the next five years here.
"I'm not saying this will be my last contract but I'd be doing well to be playing after that.
"I was pretty close to leaving last year. I was unsure of the Leinster situation.
"When Michael Cheika and David Knox came in I had to give them an opportunity and I've really enjoyed them as coaches since.
"It was all about the Leinster side of it and how the union treats players with the number of games played.
"All of that put together convinced me to stay. I believe Leinster can achieve something in the next few years."
O'Driscoll will lead Ireland for the 31st time at Lansdowne Road on Saturday when the Triple Crown winners attempt to register only their third victory over the Springboks in 18 attempts.
Try-machine Bryan Habana has been given the task of shackling the Lions skipper after being named at outside centre for first time in a 22-cap career spent on the wing.
But O'Driscoll denied Habana's lack of international experience in the position is an area to be exploited.
"Bryan is such a high-calibre player that he will adapt to outside centre very quickly," he said.
"When you get to a certain standard of footballing ability you can play in plenty of positions across the backline. He fits into that category.
"I wouldn't envisage him having too much difficulty in fitting into their system and the way they play. He's a threat one step closer into the scrum so I'm sure he's going to get more ball.
"We'll have our hands just as full as if he was playing on the wing."