She definitely 'trained' me when I was a newhire, but she quit flying 25 years ago, so I probably need to go to Jet Recurrent.

As a commuter and frequent dead-header, I get to experience the aft cabin far more than I like, and most F/A's are not bathroom Nazi's while taxiing out, but I've seen more than a few go ballistic if...God Forbid...someone gets out of their seat; "SIR, WE ARE ON AN ACTIVE TAXIWAY, YOU MUST SIT DOWN!!" even when we are stopped.

My point is, people should be allowed to get up and use the facility if nature calls, just like on a bus at 70 mph in traffic. But then I guess we'd have all lavs full of pax, when it's finally our turn for takeoff, so...why don't they just put seatbelts in the lavs and.... let it flow?