The Briton qualified third on the grid in Melbourne and was battling for a podium finish before a switch to a three-stop strategy resulted in him finishing fifth.
But although admitting that he never predicted such a good start to the campaign, he reckons that Mercedes can deliver even more soon.
"With strategy we could have been slightly better; we could have been better on our tyres, we could have done the set-up better and we could have been faster," said Hamilton, reflecting on areas for improvement for Mercedes.
Hamilton concedes that Mercedes will face a tough time pushing itself to the front of the Ferrari, Red Bull and Lotus battle, but is not ruling out anything yet.
"I think Ferrari are the most impressive, then Lotus and then Red Bull," he said. "That is my initial thought, but everyone has their own opinions.
"Lotus did a great job, and I think Ferrari was in terms of pure pace quite good. But I wouldn't count us out just yet, either."
When asked if that meant he was allowing himself to dream of the title, he said; "Definitely not. You just need to think about the car, and where it was last year.
"We came into this year expecting to hopefully be a little bit better than they were last year, but definitely not anywhere near as high as we are now.
"I am trying to aim at consistency again as I did last year, but in terms of pure performance at the moment we don't have that pure speed to be able to compete for the world title."