I always set myself new goals. I always want to do better than I did in the past. I always want to achieve things I never achieved before.

Before I arrived here [ Borussia Dortmund], a lot of people were questioning about whether I could ever play as a striker, that I was a guy who could only run down the wing quickly.

I always set myself new goals. I always want to do better than I did in the past. I always want to achieve things I never achieved before.

There are a lot of things to like about [Borussia Dortmund's fans] and the city of Dortmund as a whole.I like their honesty. And I like that my family and I can feel safe here. I don' t have to worry at all about my safety and their and my own safety. Believe me, in other countries I have made different experiences in that regard. All of this, too, has led to my decision to extend my contract until 2020, and I can imagine staying even longer.

When I arrive at our training ground at Borussia Dortmund, everybody could hear just that a few seconds before I can actually be seen. Everybody knows it's me. I love to hear the machine working.

The mentality of coaches and players alike [in Bundesliga]. It's all about winning.

At Milan when I was younger, I worked a lot on the leg press because I'd lost a bit of my natural speed as my body was changing. I was growing too fast for the rest of my body to cope and I had some knee problems. I worked really hard in the gym to regain these fast sprints.