Ammann, who will carry the Swiss flag at the opening ceremony, is the only man in Olympic history to have won four individual ski jumping golds.
He captured the normal and large hill titles in 2002 and repeated the feat in Vancouver four years ago, when he dropped strong hints he might soon retire.
The doubts about his future returned in early 2011 towards the end of a successful World Cup season where he came second. He also placed third and fourth place in the World Championships.
"It was tremendous and after that I didn't know what to do," he told reporters shortly late on Thursday after the last of three practice jumps.
"I was not really able to get rid of ski jumping. I was trying in part (to do so) but inside I felt that I really had to go on and ... find again the core of this sport," he added.
Ammann has had an inconsistent World Cup season so far and is sixth in the standings.
During the practice jumps for Sunday's normal hill event he was improving his technique to ensure the best possible lift-off but clearly had mixed success, given that his last jump was the shortest.
"I thought I must be very bold to get the right timing at the take off and as soon as I miss the right angle of visibility, or the point of balance is at the wrong place, I get late.
"And that was what happened at the last jump, the progress had been there from the first to the second," he said.
Coming into the Vancouver Games, most observers had predicted Ammann would be run close by Austria's Gregor Schlierenzauer, who in the end could only take two bronzes on the individual hills. Schlierenzauer, 24, is again one of the favourites.
Asked whether he could pull off another surprise, Ammann said: "Anything is possible. I was shuffling in my brain to make enough space for that to work ... I have lots of positive pictures already from these last few days and I try to get closer every day and the focus is getting together."
Ammann said he had also been helped by the fact his wife is Russian "so I saw that in the long term I can really accept this place where I will compete".
Ammann and Schlierenzauer are both very light and slender, which enables them to float further through the air.
After the 2010 Games, in a bid to make the competition fairer for larger and heavier jumpers, authorities imposed new minimal weight limits and cut down the surface area of skis.
Some jumpers had gained an aerodynamic advantage from wearing relatively baggy suits but these have now been replaced by much tighter outfits, which Ammann said had made the sport "more difficult than ever".