On Demo: You see a setup, you take it.

You don't "need" the win, so you let the trade breathe.
You act like a professional because there is no threat.
On Live: Every tick against you feels like a physical attack.
Your brain treats a $50 loss the same way it would treat a predator in the woods.
You freeze, you panic, or you "attack" back (revenge trading).
The Result: You are literally two different people.
The "Demo Version" is a trader.
The "Live Version" is a panicked human trying to survive.