It depends the most on the details of the situation. For example maybe the loss was massive then it will take a longer time to forget and if it is smaller it will be faster. It is healthy to do it this way. There are those people that are in denial about the consequences of their actions and they say that they can forget big losses fast. This is very unhealthy, never do this. It is a child's attempt to run away from reality and it never works. This usually leads to other compulsive behavior and mistakes. I particularly only had a big loss a few times and it did take some months and in some cases years to swallow it, but this doesn't have to be restricted to gambling. You can also make very bad investment choices which at the time sounded good.