It irks me when I see people putting their bag in an O/L several rows in front of them, so they can try and barge their way off a few rows early on landing.
I had the good fortune to get downgraded from C class to an equivalent row on an all-economy aircraft (only a quick hop over the Gulf), only to find all the bins full.
It's a tribute to Qatar's respect for their frequent flyers and business passengers that the CC simply removed a bag that wasn't meant to be there to make space for mine.
Furthermore, the chancer five or six rows back that had tried it was dismayed to see his bag go all the way to the back of the plane.
Oh how I laughed.
