The following is a true story.
I had just finished my masters in Chemical Engineering. I had decided to not use that degree because I wanted to be a developer. One of the first companies that offered me a job was this rather large company that was working on web applications; though I hesitate to call them that. Like many of the programming shops back in that day, this company was using Java as their primary language.
I specifically remember the interview because of how excruciatingly embarrassing it was. The interviewer asked me to solve a fairly famous programming problem as part of the interview process; the "FizzBuzz" problem. The idea behind this particular problem is to make a program that iterates upwards from 1 to 100. If the iterator is divisible by 3 then you print out the word "Fizz", if the iterator is divisible by 5 then you print out the word "Buzz" and, if the iterator is both divisible by 5 and 3 then you want to print out the word "FizzBuzz". Otherwise, on each iteration that is not divisible by 3 or 5 or both, you want to print out the number of iterations.
After listening to his explanation of the problem, I furiously poured over the potential solutions to this problem. About two to three minutes of deliberation passed and I started coding my example in front of him. My example was this 70 line monstrosity that featured multiple loops and arrays inside of various different functions which would allow me to determine if these numbers were divisible by 3 or 5. The interviewer was looking over my shoulder and he calmly said, "There is a much more simple answer to this problem."
I started freaking out in my head upon hearing him say this.
How could I possibly simplify this program? I started arguing with the interviewer about how there couldn't possibly be a more simple implementation. I explained my code line by line to the interviewer and told him that all of them were necessary to complete the desired output. He responded to my explanation with a fairly simple reply.
"You've never heard of the Modulo Operator, have you?"
Note: the Modulo Operator allows you to find the modulus of two numbers or the remainder of two numbers by division. Suffice to say that it cut my implementation of this program down to 10 lines of code.
Of course I knew what the modulo operator was but I couldn't bring myself to admit that to him. Face flushed red, I finished the code in less then 30 seconds.
Needless to say, I did not get this particular job. I did however, go home and wonder how I was able to complete a masters degree at all.