I don't know what it is, but it seems like I can get things done quicker with OS X. Lots of Mac users claimed that they get increased productivity on Macs vs PCs and I used to think it was a bunch of crap. But now that I'm using OS X full time I can notice a difference. I don't know if I didn't take the time to learn the key strokes in Windows, but they didn't seem very intuitive. Cut, copy, paste, alt+tab, and of course ctrl+alt+del were about the only key strokes I used.
Now that I'm actively trying to learn a new operating system I'm making a point of it to try to use keystrokes. Its making my productivity go through the roof. Which everyone knows is a big plus.
I think your atitude changes when you move to a new opperating system. Out with the old and in with the new... All the negative thoughts and reminders of bad experiences are gone. You're ready for a fresh start. Time to give something new a shot.
In rolls OS X. You're excited, amazed, and wowed. Everything is positive and because of that you're able to get things done. No more slamming your mouse when things crash or kicking your desk to retaliate against a virus. I can see why Mac users are so out spoken about loving their Macs.
If you are interested in learning a bunch of new key strokes I'd recommend the official OS X Keyboard Shortcut guide.