Forgive me if this is the wrong forum to ask this but have any of you created your own WordPress theme? I want to give WordPress a try. I've used Joomla a lot but never WP.

Have any of you done this? How hard is it to learn?

Any examples?

Yes, I've made a couple. I was really lost when I started on my first, but with help from a couple of really detailed tutorials from nettuts.com and the WP Codex you catch on real quick.

I guess the best way to start would be to begin with the default theme, it's clean and simple enough. Keep the WP Codex close at hand and just go nuts. Trial, error and tutorials is, IMO, the best way to learn.

Doing the wordpress themes is fairly simple. Since the themes and PHP code is intermingled you only have to work with one file for each section, like the header file.
Some people think that is bad and others think it is good, thats debatable. What that does do is make it easy for new users to take there HTML code and replace the section in the default theme to create a new theme.

I've made quite a few. It's pretty easy, and I usually just modify a minimalism theme to do it.

I've created a few themes. Creating your first one is usually hardest. Once you do that, it gets a lot easier.

I'd suggest downloading a theme from wordpress.org/extend/themes and having a look at it. Use it to give you an idea of what a WordPress theme looks like.