I understand this - debuggers are useful (especially when going through code you haven't written), but if you're writing an entire program yourself, you understand how it works completely, so a debugger is much less necessary (not unnecessary).
I haven't fired up a debugger for a long time, partly because I'm in to defensive programming big time. If you have something as simple as assert(ptr != NULL) in a function, if it fails, you get hit with an assert failed message, the file, line, function and condition. Most of the time this results in me thinking, "oh, duh" and immediately correcting the problem, sans debugger.
I haven't fired up a debugger for a long time, partly because I'm in to defensive programming big time. If you have something as simple as assert(ptr != NULL) in a function, if it fails, you get hit with an assert failed message, the file, line, function and condition. Most of the time this results in me thinking, "oh, duh" and immediately correcting the problem, sans debugger.