The England midfielder admitted he was "really upset" when Spanish role model Fabregas swapped Arsenal for Barcelona in 2011.
Wilshere believes Arsenal felt the loss of Fabregas more keenly than the departure of Robin Van Persie, even though the Holland striker's goals secured the Barclays Premier League title for Manchester United last term.
But 21-year-old Wilshere is confident new recruit Mesut Ozil can fill the void left by the likes of Fabregas and Van Persie's exits.
"The one I was really upset about leaving was Fabregas, I learned so much from just watching him," he told Arsenal's official club website. "He's similar to me starting at a young age.
"I was the most upset about him leaving. But to arrive I'm excited about Ozil, he's settled in nicely.
"His first game away at Sunderland he got an assist and was man of the match.
"He plays the Arsenal way and I think there's a lot more to come.
"He's so comfortable on the ball, right foot, left foot.
"If you look at his stats he runs the most, he makes it look easy but that only masks how hard he works."
Wilshere hailed boss Arsene Wenger's "special care" as the driving force behind his blossoming Arsenal and England career.
The Stevenage-born playmaker said the long-serving French manager's loyalty even through lean spells of form helps get the best out of Arsenal's young talent.
Wilshere said: "He's been the main person in my career: he gave me a chance when I was 16.
"He gave me special care, put his arm around me, he picked me out and gave me the chance to train with the first team every day and that helped my career massively, just learning from the way they play.
"Sending me on loan to Bolton, learning to play the Premier League way, that was important too.
"Some games I didn't play well but he still stuck with me when I made mistakes. If you make mistakes he sticks with you, and that's huge.
"I feel like I've been around for a long time now, I should be used to playing week in, week out.
"I'm 21 but in football ages I'm a bit older than that. I've got a few years' experience and hopefully that can help me, so I'm looking forward to the next three to four years."
Wilshere revealed he would love his two-year old son Archie to play for Arsenal one day, and also confirmed an interest in coaching when his own playing days come to an end.
"I'd like to think coaching," he said.
"Even yesterday I took a youth session and I like teaching youngsters about football.
"That's the only thing I wanted to do growing up.
"I would have been so happy growing up if a professional footballer had come back and given me some advice."