Actually everything has its own risks, including in gambling. Everyone knows that gambling never guarantees the win, it even spends a lot our money. If we have no control for our emotion, we may be influenced to spend all the money to chase the wins. Or we may be triggered to gamble as much as possible to recover the losses. This is totally wrong way in gambling, this will lead into an excessive gambling. The only way is to limit control our emotion by limiting the funds and the time to play gambling games. So, it is true that controlling emotion is very important in gambling.
One of the first thing to do in gambling is to accept that you are not going to win anything, once you accept that then there is nothing that gambling will present to that will come as a surprise to you again. The day you don't win anything, you wouldn't feel anything and the day you win, it will looks like a surprise to you because you never expected it in the first place and if you now play by the rules of gambling, you will not be emotional nor get addicted about it because you stick to your rules.
Gambling becomes another thing when you refuse to play by your own rules. For instance, you have a weekly bankroll which once you finish, you don't ho extra mile to bet another one because you believe it will go against your rule. It only become a problem when you start gambling and don't stick to your own rule by wagering more than you initially had in mind. Many things can come from it but most often, what you get is loss, you wouldn't win anything.