In almost every movie featuring a house on fire, the actors seem to be able to move around the house and see just fine, while beating back flames with a shirt or coat. Of course, that's not what happens in real fires!
When there's a fire in a home, there is typically complete darkness (because the power goes out) and a cloud of spreading thick, black smoke makes it difficult to see and breathe.
That's why knowing how to get out of your house ---fast--- is crucial.