O'Gara, a member of three British and Irish Lions tours, was named in Declan Kidney's Ireland squad for the autumn internationals against South Africa, Samoa, New Zealand and Argentina next month.
And after vowing to meet the challenge of Sexton head on, O'Gara admits he has no intention of hanging up his kicking boots any time soon.
"In previous interviews I may have said that I only plan on playing for another two seasons, but I've gone completely the other way now. I can't see myself stopping," said O'Gara.
"With hindsight it was an inaccurate way of thinking about it. Why would I put a timeline on it? The minute you stop enjoying it or when you think you're not the best man to play, then you go.
"Maybe for a few months when Johnny came on scene I probably struggled to get my head around it.
"I've been so lucky to play for Ireland over the last 10 years. You get marked hard in that position, so I'm happy to have survived and to still be in contention makes me hungry for the road ahead. I haven't been this motivated for a long time.
"I'm getting to know him and enjoy his company. If you can't get your head around the competition and treat someone as a decent human being, then you're going nowhere in life. He realises there is competition for the jersey and so do I."