Red Bull dominated practice and qualifying in Melbourne, only to slip to third and sixth places in the race as it struggled to make the Pirelli tyres last as long as rivals.
Vettel denied that he had thought Melbourne victory was guaranteed after practice and qualifying, but acknowledged the tyre situation came as a surprise that Red Bull has had to react to.
"You don't approach the race thinking that it is practically won. It is not that easy," he said in the Sepang paddock.
"Though we saw the chance to win, the problems we had in the race, suffering with tyres, we didn't expect to be that much of a problem to be honest.
"I think we learned a lot, we can improve already for here.
"Generally nowadays there is no possibility to change the set-up for Sunday, so we are looking at a couple of things. There are lot of things we learned, a lot of things we still haven't understood but then again it has only been a couple of days."
Vettel added that there was very little a driver could do to minimise wear on the latest generation of tyres once the race was underway.
"Obviously you have ability to check tyres visually, and then you try to react," he said. "There are different strategies, you try to pace yourself and react to the grip you have, but all the time you obviously try to go as fast as you can.
"Sometimes you try to go under the tyre, give yourself a little more later on, which sometimes works and sometimes doesn't.
"It's not always in the driver's control. Sometimes there is not much you can do from the inside of the car to control tyre degradation.
"Of course you can try to do less mistakes, because bad grip leads you into mistakes, so you have to adapt."