"As an actor, for me every day is a first day. Even today when I give my first shot for a film I feel jittery," the 61-year-old said here.
"It would be wrong if I say that I was confident before the shoot. The first shot in any film, I get the same feeling as I did in my first film," he added.
Mithun will soon be seen in Sajid Khan's "Housefull 2". The promotions for the film are on full throttle.
While many may think promotions need to be extensive, Mithun feels otherwise.
"Promotion is required, (but) over promotion is not required. It is important to tell people that a film is coming.
"During our days we used posters to advertise our film, but today you (journalists) are there, it is quicker, people get to know about it soon. But for me personally, doing anything over (in an over-the-top way) is not done," he said.
Mithun plays Zarine Khan's father in the film, which also features veteran actors Randhir Kapoor and Rishi Kapoor.
The movie's cast also includes Shazahn Padamsee, Jacqueline Fernandez, Asin Thottumkal, Akshay Kumar, Riteish Deshmukh, John Abraham, Shreyas Talpade and Boman Irani.
The film is set to release April 5.