I wanna learn Java

I wanna learn Java. I want it so bad. Well not really that bad , but I was always interested in working with this technology. But I never got around to learn it.
See I had this career development plan in my head. I wasn't about where or what I would be doing, instead it was about what technologies I would use and when. I started my professional career with PHP, then I've migrated to Python and now too C# .net, which was something I didn't plan for. I've always had a fondness for open source cross platform technologies. Too me, locking your self to a specific operating system is not what a modern developer should do. With so many options out there , too me, what makes the most sense is to develop in technology that is OS agnostic, instead to lock your self in a proprietary technology and thus reducing your employment chances in case of loosing your job. Is good to be flexible.
So why Java? Why not be happy with .NET, is the same thing only different package? Too me this is a philosophical question. Do I want to make my money locking my self to a company that I really do not admire, or do I want to earn my bread working in something that is open, portable and positive?
Well to me today the only logical choice is Java. And in couple of years I want to be known as a Java developer.