I use it at work, I would love to have it at home but it is not available for OS X which I do not want to understand why

MS Word on OS X has very OneNote-like features, just choose the Notebook view. I haven't used OneNote proper in a very long time (2007?), but notebook view Word 2011 does automatic lists and you can even doodle.

Might be worth a look.

You can use the web-app version of OneNote on OSX. There is also a third party client called outline (http://outline.ws) which now supports writing to OneNote files.