It's hard to put your heart into something you don't believe in.

When you try to execute on it, you stall, stuck in a chaotic eddy.

To execute on a thing you don't believe in, you have to turn off a part of your brain, the part that cares.

To become a zombie, at least in that context.

When you're executing on something you believe in, when it's in your zone of proximal development, that's when you can do miracles.

To spread your wings and fly.