Tall man living in Japan. I know how that feels. It sorta gets ingrained to always do it to some extend because if you mess up once you bang your head on the doorpost.

Of course my own house doesn’t have that issue (you’d think), but the one toilet on the second floor… so even at home you can’t relax the vigilance.

the showers here especially have always made me slouch and I'm not especially tall at 175 cm! It was only after getting a shower where I could stand straight that I realized how much I'd been slouching over the last 17 years due to low shower heads.