Neymar described his time at Barcelona as the "dream of a child" after completing his world-record move to Paris Saint-Germain.
The Brazil international's stunning €222m transfer was finalised on Thursday as he signed a five-year deal at the Parc des Princes after the Ligue 1 club agreed to meet his massive release clause.
And in a series of videos on his Instagram account, Neymar said: "The life of an athlete is made by challenges. Some are given to us, others are fruits of our own decisions to keep the light that illuminates our career, which is intense but short.
"Barcelona was much more than a challenge, it was the dream of a child who played with those stars through the video game."
Reminiscing on his time at Barca, he added: "I can still remember my first days at the club, sharing the changing room with idols like [Lionel] Messi, [Victor] Valdes, Xavi, [Andres] Iniesta, [Carlos] Puyol, [Gerard] Pique, [Sergio] Busquets and many others. Waiting my turn to play in a club that's 'mes que un club' [more than a club].
"I had the honour of playing with the best athlete I've ever seen in my life and I'm sure that I will never see another like him while I'm alive. Leo Messi became my friend in and out of the pitch. It was an honour to play with you. I made a trio with Messi and [Luis] Suarez that made history, conquered everything an athlete can conquer.
"I have lived unforgettable moments, lived in a city that is more than a city, it is a homeland. I love Barcelona and I love Catalonia. But an athlete needs challenges. And for the second time in my life I'll contradict my father. Father I understand and respect your opinion, but my decision is made and I ask you to support me as you always do.
"Barcelona and Catalonia will always be in my heart, but I need new challenges. I accepted PSG's proposition to try new achievements and help the club to win the titles that their crowd wants. They showed me a daring career plan and I feel ready to take on this challenge.
"Now I feel in my heart that it's time to leave. PSG will be my home for the next few years and I will work hard to honour all of the trust placed in my football. I'm counting on the support of all of you who's been with me since 2009.
"It's a very hard decision, but I made it with the maturity I accumulated throughout those 25 years. Barcelona, Gracies per tot [thanks for everything]. Paris, J'arrive!! [I arrive]"