Gambling is not wrong if you know how to handle yourself on your activities specially on a situation that you are tempted to bet more when you won a lot of prizes.
Knowing how to handle ? The real happening is even how much you are knowledged about the practices of handling gambling effectively, in long run you will become dumb and you will never use your knowledge for your profit making in gambling. Gambling will blend all your knowledge.
It became wrong if you are out of control and you maybe a failure to somebody else and even your family is affected, specially personal relationships.
Maybe in the beginning days it will be seeming like gambling is under your control, but over time it will take you under its control. There the actual gambling problem starts and thereafter everything goes wrong in gambling.