Learning the Finnish they don’t teach in school
Kalsarikännit (noun)
Literally: “underwear drunk”
Example of usage: “Pysyin kotona ja vedin kalsarikännit.” (“I just stayed home and pulled a kalsarikännit.”)
Less a word than a lifestyle, kalsarikännit describes a day or weekend in which the speaker failed to achieve anything as ambitious as actually getting dressed, and instead subsided into a stupor of watching Dr Phil, eating microwaved makaronilaatikko, and emptying a mäyräkoira (12 pack) of beer.