Source: This article was originally published on CNBC.

Written by: Courtney Connley, CNBC Make It

A tough boss may be challenging, demanding and even downright mean. But, that doesn’t mean they’re bad for your career.

In fact, knowing the difference between a tough boss and a bad boss can be crucial to your success. I learned this lesson as an intern at The Washington Post in 1981, while working for award-winning journalist Bob Woodward. (Yes, that Bob Woodward.)

I arrived for my internship in awe of Bob Woodward and his reporting on the Watergate scandal, which earned him a Pulitzer and inspired a movie, but I thought Bob Woodward was a terrible boss that summer because of how hard he made my life.

He routinely pushed me to go back to my sources for more information and questioned everything I wrote. He did not engage in pleasant banter. He never said, ‘Good job,’ even once when my story hit the front page of the Post — as an intern!

I remember a time when Bob Woodward bristled at my suggesting a time for a meeting, instead of asking about a time that was convenient for him. In short, Bob Woodward intimidated me.

But looking back, I realize now that he was being tough on me to toughen me up for the profession I had chosen. He didn’t care about my feelings. He cared about my career.

While Woodward, was not a nice person to work for, he was not a bad boss. Real bad bosses only care about themselves, and your performance is merely fodder for their upward trajectory, whereas Bob Woodward was already at the top. He didn’t need me to shine his star.

I now understand how the journalist’s pushing and prodding was an effort to make me better not only for my employer but for my profession. Like any tough boss, he shoved me out of my comfort zone.

Unfortunately, I ended up leaving the internship for a “nicer” newspaper, and now wonder what I might have learned had I stayed.

His lesson about the difference between tough bosses and bad bosses is still with me today.

A bad boss is about [their] own success. A tough boss is about yours.

Suzy Welch is the co-founder of the Jack Welch Management Institute and a noted business journalist, TV commentator, and public speaker. Through its online MBA program, the Jack Welch Management Institute transforms the lives of its students by providing them with the tools to become better leaders, build great teams, and help their organizations win.