In an apartment the size a US prison cell? You either have the measurements wrong or I'm calling BS on that, how do you even fit a twin bed in a 6m2 apartment? Do you shit in the sink?
Seriously, that's about the size of my bathroom. I certainly could have a smaller shower, but I'd change my tune if I had to sleep in it.
Just to give you my perspective as an Uruguayan (South American) software developer, whenever I visit the U.S. I think houses are ridiculously huge - most are bigger than mansions here in Uruguay.
I don´t have the same experience in Europe.
A twin bed isn´t a requirement for a single person. I lived in a 14 square meter apartment for 8 years, it´s not that harsh.