I still remember when we learned logo in elementary school. I had to get my mom to go out and buy a 3.5" disk so I could save my programs.

When I realized that all of logo was actually saved on that disk and I could continue playing with the turtle at home, I was amazed.

Drawing little things, realizing that I was repeating stuff and breaking it into little functions so I could draw them again more easily. I was learning the essentials of programming and didn't even realize it.