Thag brain not hear, honey

"Thag, don't forget to bring home that chunk of mammoth meat you left to hang in the forest."

No response from Thag, who is knapping flint with his whacker. He is making more flint arrowheads to replace all of those he lost on the last hunt.

"Thag?"

Thag is absorbed by his work, and does not respond to his fetching mate, Onga, despite her proximity, and his deep love for her. He is not ignoring her, his brain is simply not hearing her.

"Thag!"

The whacker slips and several hours of work are wasted