Two CPA's were returning home from a client meeting.  They took the cheapest seats on the plane so they each were occupying the center seat on opposite sides of the aisle.

They continued their discussion of the knotty tax problem that had been the subject of their client meeting through takeoff and meal service.

Finally, one of the passengers in an aisle seat offered to trade places so they could talk and he could sleep.

After switching seats, one CPA remarked to the other that it was the first time a tax discussion ever kept anyone awake.