However, I think everyone must experience such a phase, but if he continues to always think like that after losing from gambling then it can be said that he is not mature enough in his mindset even though he is old.
Sometimes age does not determine how we can actually mature, sometimes people who are young have had to mature prematurely due to events that have happened , I personally could say that to be in a casino we must know what we are facing , it is known that it is a place where you can Easily lose money and if you lose you must accept it and assume it, all that remains is to improve and nothing more.
What I can see is that life will always teach us to count how prepared we are to assume the reprisals of our decisions. We are still young but the situation makes us ensure that we live like adults. You know very well that there are never smooth sails in any direction, as you will all ways find a risk. The key here is that a person can be certain about how we can deal with the failures when things go wrong, and what we can do to recover that fail without avoiding reality.
Bitter experiences can also be good teachers in case we can position ourselves on the right side. Personally, I think we become much more mature through this process as as of being old enough. Therefore maturity based on actual experience will never be weak when compared to maturity based on numbers.