Three Swedish researchers spent time estimating the aggregate time spent folding the corners of toilet paper. They published this study (which tells only their estimate of how much time those other people spent folding, but does not disclose how much time the authors spent calculating and writing):
“From our experience the toilet paper is folded in the bathrooms in rooms in branded hotels. We aimed to study the total time yearly spent in the world on folding hotel toilet paper…. Assuming an extra 10 s spent on folding toilet paper, approximately 10 million hours are globally spent on folding toilet paper every year. This corresponds to more than 5000 man-years of work. In a hotel with yearly full coverage of 200 beds skipping folding the toilet paper corresponds to around 200 h of time that could be spent elsewhere.”
Ross Pomeroy provides additional details, writing in RealClear Science.
BONUS: In this four-and-a-half-minute-long video, Elen Correa — who is not part of the research team, and may not be aware of their calculations — shows how she folds toilet paper: