The former Borussia Dortmund winger made the £55m move to Chelsea last week.
And while he came through the youth system at Manchester City, Gittens revealed he is also a former Chelsea junior.
"It feels very full circle," Gittens told the club's website. "I was at Chelsea when I was at Under-8 or Under-9 level, around that time. I wasn’t there for long, but I remember going to Chelsea and being so excited to come back from school to join Chelsea for two hours, once a week. It was a great feeling.
"I remember playing at Reading and Manchester City and having to play Chelsea in the youth academies, so to go back to Cobham as a Chelsea player will be great."
At City, Gittens play alongside new Blues teammates Cole Palmer and Liam Delap.
"I played with Cole at Under-16s and Under-18s, and Liam the same," Gittens continued. "And I’ve played against Levi (Colwill) from every single time we’d play against Chelsea in the FA Youth Cup, Premier League tournaments, the lot.
"I had a couple of text messages from Cole telling me to come, the same from Liam, and all of them were eager for me to join."
Hazard a hero
Gittens also said, "I did watch Chelsea when I was younger. Not in the stadium but on the TV at home in Reading, during the time of the Eden Hazard era. Eden was the clear player for me at that time. I liked Willian as well, another attacker. He had that little shimmy he did, I liked that.
"It’s my dream to play in the Premier League. Obviously, watching it from Germany, it’s a really intense league. Every week is a battle, and I feel like I can enter that battle strongly. I’m excited to join this team that have a winning mentality – that’s the main thing.
"I just want to keep improving, especially as a footballer and a human being. I want to be more consistent and keep learning.
"It’s a great feeling to join Chelsea, such a big club. I can’t wait to learn from everyone in the team and to push myself to the max here. It’s amazing."