Liman, 52, directed the first installment of the Matt Damon franchise back in 2002 but as a big James Bond fan he was worried he was making a "poor man's spy movie", reported Contactmusic.
"I felt so insecure while I was making 'The Bourne Identity' that I was making a poor man's spy movie. There was someone of the set who had the 'Mission: Impossible' ring tone on his phone, and every time his phone rang it drove me nuts because I was afraid my movie was never going to be as good as 'Mission: Impossible'," he said.