Novak Djokovic has opened up on how he riled Roger Federer when he broke onto the scene as a cocky upstart but said it only fired up his quest to become the best player in the world.

The Serbian world number one is gunning for a historic 25th Grand Slam in Melbourne, where he has already won the title 10 times.

Djokovic is already the most-decorated player in the men's game, with two more majors under his belt than the injured Rafael Nadal and four ahead of the retired Federer, fellow members of the so-called "Big Three".

The 36-year-old enjoyed a storied rivalry with the Swiss great, winning 27 of the 50 matches they played.

He is gunning for an 11th Australian Open in Melbourne to pull clear of Margaret Court, who also has 24 Grand Slam singles crowns.

On Friday, Djokovic coasted past 30th-seed Tomas Martin Etcheverry in his 100th match at the tournament, looking close to his best after patchy performances in the opening two rounds.

He was asked after his victory on Rod Laver Arena to reflect on his early career as he sought to challenge the established powers in the game.

"I know certainly Federer didn't like the way I was behaving at the beginning," he said. "I think it didn't sit with him well. I don't know about the others.

"I guess I wasn't the favourite type of guy to some of the top guys because I was not afraid to say that I want to be the best player in the world.

"I was confident, and I felt like I have the game to back it up."

But Djokovic, who faces French 20th seed Adrian Mannarino in the last 16, said he never lacked respect.

"Respect is something that I was taught that needs to be present regardless of what is happening," he said.

"Obviously on the court a lot of things can happen in a kind of heat of a battle. It was a very long time ago now, 20 years since I made my first debut I think on the professional tour. It's really hard to say who liked me more or less."

And the Serb gave an insight into what drives him, saying he was fuelled by what he perceived as unfair criticism.

"If I made a mistake, I would admit it and, of course, say I make a mistake, I raise my hand, I apologise or whatever.

"But if the criticism came with no particular reason I think, then I would just keep going in the kind of direction that I chose, and that's it.

"I knew and I know today that you can't have everyone liking you, who you are, how you play, how you behave, what you talk about. It's normal. We're all different. We are all different preferences."