Memory management may never become an issue for you, it might your every waking moment, or you might find yourself in between these two polarities. Most of the time, it is a non-issue for the majority of programmers, especially with the constantly improving garbage-collection algorithms. The G1 garbage collector (default in JVM 9) is definitely a step in the right direction. But there is also a chance you will be called (or will notice yourself) about the application's degrading performance, and that is when you'll learn how well you are equipped to meet the challenge.
This recipe is an attempt to help you avoid such a situation or to get out of it successfully.