The 28-year-old striker was rushed back from a metatarsal injury for the 2006 World Cup and carried an ankle injury into the 2010 tournament in South Africa, failing to produce anything like his best form as England flopped.
"Previously I have always been going into the first game looking for fitness and it's difficult to get your breathing right and the rest of it," he told the Daily Mail.
"This time I honestly feel good. I have looked after myself as well as I can to be as fit as I can for this tournament. I will be ready. I'm looking forward to it.
"I really want to be 100 percent fit this time and, barring an injury in training before we go, I will be totally ready."
By contrast with the huge expectation that attended England's last two World Cup campaigns, hopes of success in Brazil are not high after they were drawn with Italy, Uruguay and Costa Rica in a tricky Group D.
Manager Roy Hodgson has included a slew of talented youngsters in his provisional squad and Rooney, a seasoned campaigner with 89 caps and 38 international goals, believes they could help make a big impression in Brazil.
"The players we have in the squad really excite me and I'm sure they will excite the fans," he said.
"Obviously the manager picks the squad but you can see that he has seen the potential in the young players, too.
"The last few games he has seen that and been excited and I'm sure that's in his thinking when he picks the teams."
Rooney picked out Everton attacking midfielder Ross Barkley and Liverpool's fleet-flooted winger Raheem Sterling for praise and has been encouraged by the form of his likely strike partner Daniel Sturridge and Southampton midfielder Adam Lallana.
Desperate to win something with his country at some stage in his career, Rooney believes Hodgson's squad have enough quality to defy odds in excess of 30-1 at the World Cup.
"There is a great mix and I think we can surprise people. It's exciting," he said, adding: "I believe we can go all the way in Brazil, I really believe that. We have a great group of young players.
"It's going to be difficult. There is a chance we could go out at the group stage but I really believe we have a group good enough to go a long way."
- Sports & Recreation