Villas-Boas worked for seven years as a scout under Mourinho at Porto, Inter Milan and Chelsea.
However, Villas-Boas ended their professional relationship due to limited advancement opportunities at Milan, and went on to coach FC Porto, the Blues and now Spurs.
The Portuguese compatriots will come up against each other when their sides meet in the Premier League at White Hart Lane on Saturday.
When asked if he regretted going his separate ways from Mourinho, Villas-Boas said: "I don't lose any sleep.
"Our break-up point was because I was full of ambition to give him something extra and I wanted further involvement from the job I was doing at that time.
"I felt I could give him much more. But he didn't feel the need for somebody near to him or in another position as an assistant, and because of that it was decided that it was time, after Inter Milan, to continue our careers (apart)."
Villas-Boas conceded he is no longer close with his former mentor.
"Yes, I think so. We had a great personal and professional relationship before that we don't have now," he said.
"I don't think we need explanations. But our relationship broke down. I think we have the mutual respect for each other and we understand what we have been through cannot just disappear, but it's not like it was before."