Originally Posted by
winkydink
Pee early & pee often is my motto.
I've found that if I wait until I
really need to go right this minute, there's invariably a wait.
Once on an SFO-CDG flight, I was waiting with a couple of other people for the lav. One of the waiters became impatient and started knocking on the door. After the 2nd round of knocks, a rather peeved-looking woman opens the door and said, "Excuse me, I'm doing a medical procedure." She then closed the door and was in there a few more minutes.
That once always puzzled me, but it also taught me to be extra patient.
She might be a diabetic and either checking her blood-glucose level or injecting insulin @:-).
Still broadly on-topic but in the past few months I've had a couple of incidences where I've got up to use the lav and seen the "vacant" sign on the door. But on opening the door, there has been a lady sitting on the seat

. Both times they have made me feel it was my fault

FFS, lock the door if you don't want to be disturbed