9:00pm:
Need to let the dog out.

9:01pm:
Oh, I should check the mailbox.

9:02pm:
Those buttercups around the bushes are really taking over. I'll just pull up a few.

9:20pm:
[Having cleared 10' of fence-line by headlamp, and pulled up enough weeds to fill a 5-gal bucket] Oh, right, it's time to read to the kids. I should probably wash my hands. Where's the dog?

Informal diagnosis: ADHD
Formal diagnosis: [unnecessary]