What surprised me the most is that most developers can't actually use Excel properly. Most developers struggle even with really basic Excel operations while a lot of non-programmers can do advanced and useful things with it.
For exampe: We used it once as a bug tracking tool and all business people could easily work with it while developers didn't understand that they should use the drop-downs in the cells to define the status and not type something in the cell. We had to continously fix the sheet and explain the developers. While they were complaining about Excel,it was obvious that the lack of basic knowledge of how to use it properly was just lacking.
The same is true even to a greater extent for Word processors. Only a small part of the users can properly format a document with a correct usage of headings and sections.