I began coding in IBM/LCSI PC Logo. The first line of code I ever wrote was:

  FD 100

That's the "hello, world" of turtle graphics in Logo. While probably not as beautiful as the several splendid examples posted in this thread, that simple line of code changed my world. I could make stuff happen in an otherwise mostly blank monochrome CRT display. Until then I had seen CRTs in televisions where I had very little control on what I see on the screen. But now, I had control. The turtle became my toy and I could make it draw anything on a 320 x 250 canvas.

The next beautiful piece of code I came across in the same language was:

  REPEAT 360 [FD 1 RT 1]

The code above draws an approximation of a circle by combining 360 short line segments. It showed me how control flow can be used elegantly to express complex ideas in a simple expression. And then I came across this:

  REPEAT 20 [REPEAT 180 [FD 1 RT 2] RT 18]

The above code draws 20 overlapping circles. The output looks like this: https://susam.in/files/blog/dosbox-logo-1.png .

At an impressionable age of 9, reading and writing code like this, and using simple arithmetic, geometry, logic, and code to manipulate a two-dimensional world had a lasting effect on me. I like to believe that my passion for software engineering as well as my love for writing code, sharing code, and open source development are a result of coming across these beautiful code examples early in my life.