I've gone through several stages.
As a kid I was shy and self-aware, so it was always door closed and double locked.
Then as a wild young man busy mis-spending my youth (and what fun it was too) I was a door wide open guy. In one small flat, I even removed the toilet door to have more room.
Then I started hanging out with deaf people - where door open indicates noone in the toilet, but door closed indicates someone in (shouting to ask if the toilet is free is no use) - so I followed that custom.
Then I met my current partner, who was quite into feng shui and energy flows, who explained that flushing / draining water symbolised money draining away, and hence to always keep the toilet lid down and the bathroom door closed as much as possible. So now following her suggestion, I'm a doors closed guy (but rarely locked). Seems to work - I earn more than before, and save better too 😎
(blimey that was a wierd post)