The France defender says Zidane was key to his original decision to join Real when leaving Lens.
Varane said: "When Zizou called me, it was a rather eventful period and I was focused on a period of exams and avoiding relegation to the second division with Lens.
"It was a night when I was a little tired and I did not recognize him at first. When I recognized him, I was a little stressed and I asked him very politely that we meet at another time. It's a funny anecdote that marks my career.
"Since then, I'm lucky to have him as a coach."