I think we have strained your tired brain enough for one day.

At first his tired dulled brain could not comprehend what had happened.

Her tired brain could not deal with the contradictions, so she stopped trying to figure it out.

Then even his tired brain began to function at last.

If only his tired brain would tell him what it was.

I don't think my tired brain can manage this.

Try as he might, his tired brain would not give itself up to unconsciousness.

I demanded, as the responsibility now resting on me became apparent to my tired brain.

Tally's tired brain struggled to make sense of the objects in the case.

My tired brain is trying to work out a response which it's failing to do at the moment.