I found this necessary because I tend to remember the "oh, this happened earlier..." but not the "... and this is the approach we followed succesfully" that should follow. The information is slotted in my brain, but not accessible unless I have some key reminder.
Also serves as a communication device between my past and future self, and between coworkers. The error-solving information tends to live transiently in your and your coworkers minds, and it is very valuable.
I haven't solved the method to properly identify-and-recalling. I simply save new information per project, per language, etc, with not much thinking. This would clearly be the next point of improvement.