One thing that I've always wondered about are the cleaning habits of other people. I've stated numerous times that I live in a pigsty, and visiting other people's homes always makes me feel self-conscious and a bit guilty.
There is a programme in the UK called "Who Does What?" that uses cameras in the home to analyse the division of labour in the household. After a few weeks the data is reported at quite a granular level of detail and the various inhabitants of the house are told what percentage of various tasks they do, and what percentage of tasks overall.
This show reported that the average person spends 30 minutes a day "cleaning and tidying" the house. Interesting. I do substantially less than that. I do essentials like laundry, but that's a fairly quick and easy job twice a week. I don't really do the "other half" though...the clothes come out of the machine and into the wash basket (or on a chair / door etc) and they get picked at and used as needed. I don't really put clothes away. I iron my work shirts too so that's maybe one or two shirts a day depending on what's on TV when I'm ironing (if I do two shirts I won't iron at all the next day). I do the dishes when there are no clean ones left, so maybe once a week, twice at most. Rubbish and recycling tends to lie where it falls and I gather it up once a week on the night before rubbish day, though sometimes I only do that every other week.
And that's about it really. It's no wonder I live in a pigsty.