it is painful when one losses game even though he didn't express himself out. But he might tell his friends that the game that he loss was painful and some would encouraged him. Gamblers that didn't not feel that way are not much. Those who are playing for fun feel that pain because they are not expected to loss perpetually. It is when you win and loss that make the gambling more interesting.
But coming to the demo account, you don't have to be worry when using demo account because you loss nothing. Though you will feel small remorse but when you realize that it is demo then you pick courage and play again.