His last Test outing was against the All Blacks last June when the infamous spear tackle executed by Tana Umaga and Keven Mealamu ended his tour.
As Lions skipper it was a shattering way for O'Driscoll's time in New Zealand to be cut short but the bitterness he felt has since been replaced by a more positive outlook on his professional career.
"It's all about gaining experience. The older you get the wiser you get and you must expect good and bad," he said.
"I've taken what happened on board and have learnt from it. Now I'll relish the good opportunities and good wins that little bit more.
"Last summer was probably the biggest disappointment of my career but now I have something bad with which to balance the good. I will no longer take anything for granted."
He added: "It's a lovely feeling being back. It's not just relief - it's nice to be around the camp again and to feel the excitement surrounding the Six Nations.
"The build-up for Italy has been good and it's a great feeling to be involved in big Six Nations games. I'll relish Saturday's as I've always done."
O'Driscoll's has made four appearances for Leinster since his comeback began on Boxing Day and has improved with each performance.
The 27-year-old's masterclass in the 35-23 European Cup victory over Bath 10 days ago was the finest yet, signalling a magnificent return to form.
But he revealed there is still more to come.
"I was never worried after the surgery. There's an element of frustration when you see the injury has totally healed but don't have the movement you'd like," he said.
"But the closer I got to playing the more confident I felt. And that confidence grew with each game I played. But there has been no particular point where I've said I am where I want to be.
"There's another five or 10% to come from me yet. I got lucky against Bath - we had some good ball and I played well. You get good games like that.
"As long as I continue to do the simple things right and create then that makes me happy. It happened for me against Bath but people were putting the ball in my hands as well.
"I'd missed a few tackles in the match before that. I needed to feel confidence in my shoulder when I was making hits and I got in a few against Bath, so that made me feel good.
"I feel sharp, my skills are improving and we have been training at a higher intensity this week. I don't want to let anyone down on Saturday."