I think of it in terms of resolution: in a finer topology, the open sets "distinguish points more". For instance, fewer sequences (or nets) converge, and fewer functions with the finer space as the codomain are continuous. This is directly because points are more distinguished from one another. On the other side, more functions with the finer space as the domain are continuous, because the requirement "close points get mapped to close values" has to be checked on fewer points in the domain (again because points are more distinguished from one another).