I can almost always lucid dream, but I’ve never been able to turn into not-me. No issues with flying (except the damn power lines in the way), sexy-time-on-demand, using doorways as portals to wherever I want to go, etc, but if I try to become not-me, I wake up. Can’t say I’ve ever tried to become a cow, though.
Possibly influenced by movies and games, I'm not-me in my dreams all the time. I've been all kinds of people, animals, aliens, non-corporeal entities etc, but as soon as I realize it's happening, not-me instantly becomes me.
It's hard to dream of something you can't experience or imagine. I wonder if role playing a cow in full costume would bring them closer to their dreams.
If you weren't chosen by Aximili-Esgarrouth-Isthill to protect your planet I feel bad for you, son: I got 99 problems but lacking the ability to shapeshift into the animal of my choosing ain't one
The only time I've ever been able to just make something happen by wanting it badly enough in my mind was turning on the radio and hearing the song I was singing in my head begin to play at the exact spot I was at in my head.
I always try things like this when I realize I'm dreaming, yet it never happens on command. Like if I want something or want to be somewhere, I can never just make it happen instantly, but if the thought lingers in my head long enough it'll sort of manifest itself in the dream.