The former Bayern Munich striker says he's joined Barca to help them return to the top .
"I think too much time has passed for Barcelona without winning titles," said Lewandowski. "I think it's the perfect time to win some titles and I'm sure it will be.
"When I first knew that Barcelona was interested in bringing me to the club, from the beginning I knew it was the perfect time for me and for the club.
"I did not want to play all my life in the same League. Everything went well in the Bundesliga, it was a good experience for me, but I knew that this was the moment to go to La Liga and take another step forward in my career. It is the perfect time for me and also a great challenge. I'm ready.
"It was enough for me in Germany. I always had the dream of playing in La Liga and now I'm here in Barcelona, I'm very happy to be here. We want to do well this season, it will be exciting for us. We hope that at the end of the season the Barcelona fans will be very happy."