Why Can’t I Juggle In My Dreams?

Can you juggle in your dreams?  I can’t.  Whenever I’m juggling in my dreams I’m uncoordinated and slow.  I wonder why that is?  When you’re dreaming, you can do most anything else, I don’t see why juggling is different.  In fact, juggling is so dependent on muscle memory I’d think it would come naturally.  Maybe it has something to do with juggling relying on a real environment (with gravity) to make it possible, and your mind can’t recreate that perfectly.  I was thinking about this the other week when I was watching Inception.  If you could juggle in real life, you wouldn’t even need that personal object to test if you were in the real world.  You could just try and juggle, and if you were awful, then you’re dreaming.  Or you’re just an awful juggler.