It was only once, he was a acquaintance. I did not much about his personal life of his habits when came to gambling. Though, it turned out there was a new casino in the city and he started to get much fun there, until he got addicted without even realizing it.
He lost much of his cash and his possessions and the last time I knew about him, He was selling his truck to settle down his gambling debts.
How are we supposed to react about them? He must have empathy, I think. We are talking about people like us, after all, and addictions like those are something which could turn our life outside down at any time we we are not careful enough. So that is what one is supposed to feel: empathy and understand that there is nothing to be done if the person is not willing to change their life.
when they gamble, of course they will subconsciously be attracted to gambling continuously and indeed this makes them addicted to gambling, even though they are not aware of it, they will realize that maybe when they have experienced a lot of losses, such as losing a large amount of money. or even lose assets and properties previously owned because they were sold to gamble again or pay off debts that surrounded them as you said. Instead of gambling at the start by having fun, it ends up putting them in trouble. and I don't think they would tell of his gambling until he found himself in fatal trouble.
What you say is correct, of course addiction can change our lives at any time, especially if we gamble brutally, continue to gamble without paying attention to the losses that often occur. there is no other way than to advise him to stop and think about what has happened so that they do not commit brutal gambling. unless we really don't care about other people then let it be, maybe they will realize it someday by themselves.