The system crashes in a portion of the codebase you have never seen. It is Friday night, 4 o'clock pm, and you have to fix it before you can go home. How can you accelerate your understanding of the bug and still get out of the office before 5?
Learn to use two simple techniques to isolate the problem by dividing and conquering code without necessarily understanding it. Once the problem has been isolated you will have a suite of tests that replicate the error, and allows you to simply debug to find the problem. After the problem is found, and you have tests replicating the error, you will have everything you need to fix it.
The best part of this is that you, the audience, will be the ones who will solve our code problem. It will be your understanding that allows the poor hapless programmer to enjoy the rest of the conference.
These techniques are generally language agnostic.