Nailing an interview is hard, especially for your dream job. That's why bestselling management author and CNBC contributor Suzy Welch says regardless of how qualified you may be, you never want to make the mistake of acting like you've already sealed the deal.
In fact, she says, it was this common mistake that cost her a job in 1981, when she was a recent Harvard University graduate.
"I wanted to be a journalist," she tells CNBC Make It, "so I sent my resume to about 50 newspapers from Maine to California, and pretty soon afterward, the Kansas City Times called and asked me to come out for two days."
On the first day, Welch says her reporting try-out went well and she was told she did great. "That was the beginning of trouble," she says. "I started acting, you know, a little too relaxed. Too casual. Too familiar."