Quite often Clojure hackers need to interoperate with various Java classes. To do that they have to import those classes into the namespace. It is easy if you know the full name of the class, together with its package, but what if you don't? In that case you have to google where the sought class is located, and then type in the whole path to it.
Java developers who use any decent IDE are not familiar with such problem. They just type in the short name of the class, and the auto-completion offers them the list of all classes short name of which matches what they typed in. But can we have something like that for Clojure? Of course we can!