You will be familiar that people don't keep their success as a secret but they must keep their defeat as a secret so same is the case with gambling which is consider as a bad activities by this society and people get failure by involving in this activity therefore may be they are keeping it secret.
But there is nothing which remains secret always and one day secrecy becomes out either in a type of success or in a type of defeat. Gambler is a person who will start gambling with keeping in mind that they will earn huge money but the outcome is not according to their hopes.
But some people keep their successes and losses a secret because they don't want people to see them. It's better for them to feel normal, like most people, so that people don't feel like they have something that makes them suspicious. However, if they can share their secrets about their gambling activities, they may be able to get help from others so they can start to cure their gambling addiction. However, some people hide their gambling activities because they feel they can still manage their gambling activities well, so they don't feel the need to tell other people.
But no matter how clever people are at keeping secrets, one day it will be known by others so that it might cause internal problems for them. Often, this even triggers fights in the household if it is a husband and wife relationship and the wife finds out her husband is gambling.