When did I begin to feel like a programmer?

Answer:  Exercise 5.41, Chapter 5, Control Statements, Part I - Visual C# 2012 (Dietel).

Yes, that was my "a-ha" moment. It doesn't seem so pivotal, chapter 5. Here's why it was a turning point:

The encrypt/decrypt exercise. I wanted some extra practice after I finished my lab assignment, so I picked the last exercise in chapter 5 to do. See code here. (If you can't see the code, let me know. I am in the very beginning phase of learning GitHub.)

In the exercise, the user enters four digits, 0-9. Each digit is first encrypted and then the digits are swapped (first with third, second with fourth). That part was easy. 

The second part of the exercise is the decryption part. At first, I was stuck. I assumed I need to concoct some complex math formula to break down the encryption, but everything I came up with failed to work in all scenarios. I assumed the failure was due to my very weak math background. It is rather anemic.

But then I saw the problem for what it really was - a programming problem. My failure was in addressing it as a mathematical problem. What I finally realized was that a good algorithm, utilizing components of math, yielded the correct results. The emphasis should have been on the algorithm and not some convoluted formula. I couldn't see the forest for the trees.

As you can see from the code, my solution was this:

First, add "1" to each encrypted digit to avoid having a negative number in the fourth step. 

Second, subtract "7". This gave me the decrypted numbers, except that there would be some double digits. Third, swap the numbers back to their original places. 

Fourth, use modulo (dividing by 10) to get rid of the first digit of the double digits (ex. 12 becomes 2) without losing the single digits (ex. 3/10 has a remainder of 3).

When I started law school, I recall the learning curve the first semester being practically vertical. But I worked hard to learn to think like a lawyer and the learning curve flattened out dramatically the second semester. By the time I started my second year, it was all routine.

I realize this encryption exercise is very simplistic, but it taught me an important lesson about troubleshooting. Sometimes, it's a matter of making sure you have the right logical perspective. While  I have a long way to go before I can call myself a programmer with any confidence, chapter 5 helped me climb higher on the learning curve.