A few years ago a high school senior, Tina, spent her "Career Week" working in the office. Tina was bright, energetic, and eager to learn. The team took turns having "informational interviews" with her and tried to cram as much mentoring as possible into a week. We also gave her assorted administrative tasks to make sure she was exposed to the office logistics and could learn that we didn't just sit around and talk.

One of Tina's jobs was to take care of the mail for the office. Our company mail isn't delivered to the suite, but it lives in the bowels of the building. It's deposited every afternoon from what looks like a Post Office Box.

The first day of Tina's mail routine seemed to go fine. She left with outgoing mail and returned with incoming mail. The second day was odd though because she returned with the usual incoming mail, but the stack also had the previous day's outgoing mail. On day three she returned with two day's worth of outgoing mail.

It didn't make any sense.

Everyone was confused. We asked Tina to describe exactly what she did with the mail. Step by step she led us through what should have been a straightforward process. When Tina described taking the incoming mail OUT of the box and REPLACING it with the outgoing mail, we gasped.

Ah ha!

Tina was treating the office mailbox like her home curbside mailbox, which served as both the ingoing and outgoing point.

I remember her indignant shock as she asked, " why doesn't your mailman PICK UP the mail out of your box??"

We had neglected to tell her that outgoing mail had a stand-alone slot.

In the brilliant book Made to Stick this is called "The Curse of Knowledge." The concept is that when you've internalized information and then you try to teach it to someone else, inevitably you leave something out. Chip Heath defines it this way:

"The Curse of Knowledge: when we are given knowledge, it is impossible to imagine what it's like to LACK that knowledge."

In the book's example you don't tap out all of the notes to Jingle Bells when you demonstrate the tune. Instead, half of the beats stay in your head. In the real world, you forget to tell your young intern that sometimes mail boxes are just used for picking up mail and that outgoing mail goes in a different place.

The more experience you have in doing something, the more likely you'll have the Curse of Knowledge. I also call it The Mailbox Mistake

As you lead your team - as you teach your children - as you mentor the next generation, be diligent in explaining not just what to do, but pay attention to see if the results make sense. Make sure the transfer of knowledge is fully operational. If not, you may find the "incoming mail" looking suspiciously familiar.

Where have you experienced the Curse of Knowledge?