This morning I discovered that the hard drive on my Mac was completely full. Zero empty space. I discovered this when I tried to check my email, and I couldn’t even download one message. I had about 50 gigabytes free a week ago, and haven’t downloaded anything. I have no idea why the drive is filling up.

This is not a good situation.

So I deleted several gigabytes worth of stuff and called a guy, who is currently booked through the end of the month. I’m hoping the free space will last until then, and that he’ll be able to take care of the problem. Otherwise, I’ll just to buy a new computer.

Why am I telling you this? Because I see it as a metaphor for leadership. (As a leadership speaker, I see lots of things as metaphors for leadership.)

Some leaders, to put it simply, are too full of their own self-assuredness to download any new information. And any leader who is unable—or unwilling—to accept new information is, quite frankly, a risky leader.

Have you ever worked for a boss who is so convinced that he’s right about something that he simply won’t listen to any ideas or evidence that conflict with his belief? Even when confronted with indisputable facts contrary to his position, he just digs in his heels further and refuses to budge!

Maddening, isn’t it?

This, for the record, is not leadership!

Look, if you, as a leader, want to believe that two plus two equals five, that’s your prerogative. But if you are then shown incontrovertible proof that two plus two actually equals four, and you continue to claim the answer is five—that doesn’t make you strong, that just makes you stupid.

A leader has to have the mental room for new information.

Don’t get me wrong. There’s nothing wrong with a leader who conveys self-assuredness. Leaders have to project confidence. Think of the leader as the pilot of the plane. How would you feel if you got on a plane, and your pilot came on the intercom and said this:

Uh, hi everybody. This is your captain speaking. Today we’re going to…(hey Dave, where are we going? Portland? Which one, Oregon or Maine?) Okay, it looks like we’re going to Portland, Oregon. Now, if I can just figure out which one of these buttons starts the damn engines…MAN, there are a lot of buttons up here!..we should be on our way.

No, you want your pilot to have confidence in his or her abilities. But if, halfway through the flight, your pilot gets an updated weather report warning of thunderstorms straight ahead, you’d want them to alter their course, wouldn’t you? In other words, you’d want them to have the mental room to accept that new information and change their plans accordingly.

As a leader, you are the pilot for your team. So be confident about your abilities, but open to new information.

Like a computer, a leader who can’t accept new information is useless. And, like a computer, a leader who can’t accept new information can be replaced.