A better model for thinking of users is to realise that they are not stupid, just busy and distracted. From an app point of view you can count yourself lucky if you get even 10% of their attention at any given time.
Users aren't thinking about your app when they use it.
That person in MSWord isn't thinking about the ribbon bar. They are thinking about how to address that new prospective customer.
That person in Excel isn't thinking about cells either. They are thinking about whether Robin in R&D is going to get the figures for Q2 to them in time.
Users have tasks to concentrate on. They don't have the attention left over to deal with your app's crappy UI.
Users aren't thinking about your app when they use it.
That person in MSWord isn't thinking about the ribbon bar. They are thinking about how to address that new prospective customer.
That person in Excel isn't thinking about cells either. They are thinking about whether Robin in R&D is going to get the figures for Q2 to them in time.
Users have tasks to concentrate on. They don't have the attention left over to deal with your app's crappy UI.