"How in Christ's name did you ever find that one?!"
When you are young in a new industry you do not to know that something is supposed to be "impossible". The system malfunctions - and it's your job as System Support to alleviate, diagnose, circumvent, and fix the bug in the developers' code or hardware - pronto. Usually such elusive bugs are found by a combination of serendipity, luck, and lateral thinking. It helps to have an obsession with trying to understand how other peoples' software/hardware designs "actually" interact - rather than how they all think it "should" work.
When I look back on some of my bug diagnoses it is amazing that I found the root causes in a short elapsed time. Many times it was a case of tripping over a pointer to the right answer whilst pursuing the "obvious", but wrong, answer. Unofficially I was the "lucky rabbit's foot". When all the specialist experts had failed to find the cause - then it was given to me. You don't learn that aptitude - but it takes a lot of practice to hone the talent.
BTW the title of "Wednesday" was meant to refer to a similar "wrong address location" bug - but I couldn't remember all the convolutions of that one.