Like a typo, but
in real life.
A braino
normally comes in the form of words or parts of words being missed out or swapped around when somebody is speaking, often completely altering the meaning of what
the person said.
When it occurs, the culprit normally doesn't notice they did it until a few seconds later, and often not until it is too late.
"I'm feeling fine and
walking the dog" becomes "I'm walking fine and feeling the dog"
(A simple but often
devastating one...) "I wouldn't like that" becomes "I would like that"
"I sat by
the shore" becomes "I shat by the sore"