I had something similar and wondered if it was Absence Seizures. I'd sort of sit and stare and not really have any concept of time - but never sat for more than a few minutes. I was going to go to the Neurologist for testing but after I inquired about it the episodes sort of stopped. If they happen again I will probably go in and try to find out what's causing it.

On a lighter note.....ever since reading the title to your thread I can't get the song "Row, Row, Row Your Boat" out of my head!