I do not disagree with you and it is my mind saying thing that controlling emotion is too hard and almost impossible to a lot of people (majority people can't control emotion and it is not possible for them) and that is why people become loser and loser dayyy by day and if win then still they can't utilize the fund in a proper way and that can be in lost today or tomorrow.
Those who have problems with self-control will always face this, no matter whether it is a win or a loss, these are all emotions. Sometimes a win can bring a good win and these are also strong emotions that need to be controlled, so that in this euphoria you do not immediately put all your money on the next bet. You can decide that you are lucky now and you should continue playing, or just want to continue playing on positive emotions, in which case you also need to be able to control yourself.