Most PowerBI tutorials use simple, unrealistic Excel spreadsheets or csv files as data sources for Power Query. The speed and accuracy importing these samples is impressive. In the real world, however, Excel spreadsheets can be messy, with repetitive columns and rows, multiple worksheet connections, and mixed data types (to say the least). In this session, I'll demonstrate how I connected to an unworkable (as in 2+ minutes to recalculate) spreadsheet and created a data set which could be analyzed in PowerBI (and updated as necessary from newer versions of the spreadsheet). Although much of the original process was generated through the Power Query UI, we'll take a look at the M code to see what's going on under the hood. If time permits, we can also take on attendee's spreadsheets as a group and see what we can do to make their day.