What fascinates you about programming?

It's a mix of puzzle solving, optimizing, tool building, skill building, and just getting comfortable with the tools.

There's quite an ego boost in actually solving problems for people. Being the one who is the hacker of last resort, etc.

Many of the finer points are like being able to fix a Cesium Beam Atomic clock... not very useful in real life, but lots of bragging points, none the less.

Everyone says that if you write the most difficult program you're smart enough to write, you won't be smart enough to debug it, so I'm wondering what would happen if I tried. Would some finite piece of code keep surprising me for the rest of my life despite being an artifact of my own mind?

How we expand the art of "describing behaviors to our machines" from < 1% of the world ( who can program ) to the other 99%...

I like to see my ideas come to life, and to know them inside and out.