Yes, that is a mentality that must be possessed by a gambler, as you said that from the start we must be ready to lose and that is the reason why it is always recommended to only bet with an amount that you can afford to lose, there are many benefits of that mentality, first it can prevent us from excessive emotions that can lead us to various actions beyond control, second our mental and psychological will remain awake, actually everything is interrelated.
Another thing is really not easy to reach the recovery phase or return something that has been lost, remember that gambling is based on probability (possibility) meaning nothing is certain and there is no guarantee either, and that is the reason why a gambler must always apply limits, not only on the amount of money wagered but also on your expectations of winning, as you said, namely gambling reasonably.
We are making it sound easy to recover but you're actually right.
The phase of recovery isn't as easy as what we say. But the encouragement remains there and if someone is on a verge of losing a lot.
And they're able to read it, that will encourage them to do better and recover with enthusiasm.
Actually, to reach the recovery phase can be easy and can also be the opposite, everything really depends on luck, meaning that a gambler can win quite a large amount that is equivalent to the amount of money lost in several previous sessions, but of course that is a very rare situation, the existence of the dealer's advantage always thwarts luck from coming. On the other hand, of course the urge will still be there, especially if they are not responsible, in my opinion getting better is not always about success in achieving recovery, the most important thing is to understand and realize that that is what gambling is like.