Brazil-born Cacau, who became a German citizen last year, scored twice in Germany's 3-0 friendly victory against Malta on Thursday that kicked off their preparations for the World Cup starting in June.
They were the VfB Stuttgart striker's first goals for the national team on his sixth appearance but confirmed he is in superb shape going into the tournament, having scored 13 league goals.
"It is quite unbelievable what has happened to me in the past few years," the 29-year-old told reporters after the match in Aachen.
"Nine years ago I was in the ninth league with Turk Gucu Munich. Now I play for the national team. The World Cup participation is the crowing moment. Germany has adopted me in a way," he said
Cacau, who started his career in Brazil with Nacional Sao Paolo, was expected to miss out on the World Cup with Schalke 04 striker Kevin Kuranyi poised for a recall.
However, coach Joachim Low did not pick Kuranyi and said he would be travelling with six strikers to the tournament, including Cacau, who scored 11 of his 13 league goals since the winter break to help his team clinch a European spot.
In comparison, Germany regulars Lukas Podolski and Miroslav Klose scored only five league goals combined. Mario Gomez also hit the target fewer times than Cacau.
"I am just happy the coach trusts my strengths. I am not a striker who waits up front. I move and I like to come out of the defence," Cacau said.
It is exactly that versatility, as well as his powerful long-range shot, that Loew wants to have in his arsenal at the World Cup where Germany face Australia, Serbia and Ghana in the group stage.
"It is no accident that he is in the team," Low told reporters. "He has these qualities that you do not find in many strikers. He picks up the ball in midfield, has speed, always goes forward," Loew said.
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