The 35-year-old will face a side managed by Mourinho for the first time this Saturday as Tottenham host Chelsea at White Hart Lane.
Villas-Boas, who worked under the Chelsea boss at Porto and Inter before taking charge of the Portuguese side Academica de Coimbra in October 2009, says he separated from the 50-year-old because he wanted more freedom in his career.
|20/1||Tottenham are 20/1 with William Hill to beat Chelsea 3-0 on Saturday
"I was part of his staff, but I was never his assistant. That's one of the reasons we went our separate ways. I thought I could give him a lot more, but he didn't feel the need to have someone next to him.
"So I decided to give myself freedom and think about my career, which wasn't difficult. Yes, there are similarities: Porto, Chelsea. But he has had a lot of success at Chelsea and I didn't have a good experience there."
Villas-Boas insists comparisons between himself and Mourinho are not accurate and claims he has an entirely different approach to management when compared with the Chelsea manager.
"The comparisons are difficult to accept for different reasons," Villas-Boas continued.
"When you start your coaching career, everyone looks at where you come from. I learned with Jose Mourinho, but I'm completely different to him in terms of personality, way of working and communication.
"We have different philosophies. Of course, Jose has been very important in my career, he's enabled me to step back and look at things, and given me experience that I would not have been able to have with anyone else.
"We had a super working relationship, we won, but as soon as we parted ways, I started doing things my way. The comparisons come from the media. And the first difference is our personalities."