That's the simple truth, addiction doesn't come one Day but it may start off gradually as a fun untill it becomes a strap. That is how every addicted Gambler once started untill it get worst. One thing people do is that they keep on doing same thing repeatedly and hoping for change where as there are no hope.
Some people just don't understand themselves and how to monitor their activities. I mean to be able to detect and know when they are no longer following something normally the way they used to and learn how to learn and adjust before it gets worse.
Some addictions also start with where the gambler might have experienced a streak loss, and in the process of that loss obsession, they get themselves into a deeper mess that they are not willing to let go of, and the more they try to recover their loss, the more of a dip they get into and the more loss they have.