scatterbrain

(noun) a person who is disorganized and unable to concentrate

Example Sentences:

A: Why are you late? You were supposed to meet me at 1:30?!
B: Sorry, I thought it was 2:30. I’m such a scatterbrain today.

Mike felt like a scatterbrain because he didn’t sleep well the night before.

Don’t be a scatterbrain, try to concentrate!

From the Blogs:

I’m too scatterbrained to have a blog

Media:

Similar idioms:

1. scatterbrained
2. zoned
3. sleep like a log
4. sleep soundly