Some science behind the scenes

Bozone

The substance surrounding dippy people that stops bright ideas from penetrating. The bozone layer, unfortunately, shows little sign of breaking down in the near future.

[sorry my joke]

The protective layer of space that surrounds stupid people. This layer keeps all intelligent thoughts and witty remarks in, while keeping all helpful information and good jokes safely out.

Or:

The thick layer of air that surrounds a person to stop smart ideas getting in.

[sorry Serge's joke]