It's just different, and so the failure here is that you have learned how to sort files in Windows XP, not how to sort files in pretty much any OS. So when presented with something that isn't exactly like Windows XP, you're at a loss.
You've specialized when you should have generalized is another way of putting it. Instead of learning Microsoft Word, you should focus on learning word processors, for example. About 95% of all functions are the same across any word processor you come across, it's just sometimes they're called something different or in a different location. So MS Word may have a toolbar option for making say drop caps, and OpenOffice Writer doesn't. If I think about what it is I'm trying to do, it's a manipulation of the font, so if I start looking at all font related options in OpenOffice Writer, odds are good I'm eventually going to find what I want. I don't just give up the second I don't see a toolbar button that looks exactly the same as MS Word's.
And of course, ever since Windows95, when Microsoft suddenly discovered that there were TWO buttons on most mice, a good rule of thumb to live by is: When it doubt, right click.
If it's one thing you can't count on in life, it's that things change. For better or worse, they change, and you either adapt to those changes or you get left behind. Life is actually quite a bit easier if you're flexible enough to roll with the changes as they come along. You can fight them, but you'll always loose in the end. It's like trying to stop a river with only your body. You might succeed for a little while, but ultimately the water will find a way around you.
Also, for the record, I'm typing this on an iMac, and I'm employed as an ACMT (Apple Certified Macintosh Technician). I also have another system running Win7 that was my desktop before this, and is now my disaster recovery slash HTPC system. I've also run Linux off and on since about 1995, including probably a 1-2 year stint of it being my primary desktop OS back around 1999-2000. I use whatever suits my needs at the time. I'm not beholden to any particular OS, I just find certain comments to be intellectually lazy and of absolutely no constructive use.