I've made a series of test stories from my favorite test runs. This 2-days user experience test run is without a doubt the most extensive test I ever did in the smallest amount of time. These were not average 8-hour workdays, these were meticulously planned sessions that fit into my timetable with great precision and lasted from morning to evening.
The short answer: A lot. In December 2015 I was called to the offices of a project, who went live with their website the month before. On the website, customers could search for and buy products that could be sent to other people via both physical and virtual shipping channels. And they wanted me to test the "user experience" of the website on different platforms and devices.