only one answer for that. the "feel" is totally different. in demo you don't need too much worry if you lose because even if you win, you won't get anything either for real. when you trade in real account, you "feel" the worry, greediness, fear, gambling, luck, everything you name it, because you know that if you lose, you will lose real money, and if you win, you will cash out real money as well. so emotionally will be totally different. with different emotionally, the result will be different too.