[tayo42]

Your not going to know your classes, parameters, how data should actually be laid out in storage or represented in the application until you start writing anyway. It's always an iterative process.

[habinero]

Kind of, but not really. Those things are hard when you're learning, but they're pretty trivial after some experience.

I almost always have a pretty good idea of what I'm making and how I'm going to make it before I start.