I was taught in my first CS class how to use a debugger. It didn't do me much good to be setting breakpoints and stepping through my code when most of what I wrote was "Hello World!". I pretty much ignored the debugger from that point on until I learned to use GDB in a much more advanced course while working on a "binary bomb" homework assignment.
Since I've been out of school and working I've spent a lot more time using a debugger and learning how useful it can be. I would say that learning to use a debugger includes three things - a need for one, being taught/learning how to use one, and experience knowing how to use one to your advantage.
Also, spending some time learning "echo debugging" can be worthwhile for those situations when a debugger isn't available/necessary. That's just my $0.02.
