Estevao formally left Palmeiras for the Blues this summer, with Thiago Silva having left Chelsea last year for Fluminense.
He told Sky Sports: "We had a short conversation. He came to talk to me and asked if I wanted to sign for Chelsea. He told me it's a club with an incredible structure.
"I was really happy because Thiago Silva is an idol of this club; it was incredible.
"I don't feel like I've adapted 100%, but it went better than I thought. The overhead kick I nearly scored against Ajax? Sometimes I don't even know how I manage it.
"I do it naturally, like the overhead kick in the Champions League: I saw the ball and couldn't think of anything else. It's instinctive, I don't know how to explain it."
Estevao added, "Sometimes even the guys here at Chelsea say to me: 'Is it possible you're 18?!' And even me, when I'm in my room playing video games, I say to myself: 'I'm only 18.' I don't even know how to explain it."