I feel as if modern keys promote failure to ensure the successful
locking of a door on *every* occasion.

I'm super vigilant of late but some years ago I was surprised how many
times I was getting home to discover the front door wasn't actually locked.
I can only presume it was down to that extra turn they need, which if
you don't and further don't try the handle, fail.

Just had a new door on at work, it's a Yale lock, a stupid flat key that
you can't distinguish which way around it is to ensure you get in the
right way first time and it only comes out horizontal, which after you
give it a good old turn, needs turning back on itself to get the
frigging key out.