Trust! Trust is flexible by nature. It's like pouring water on paper and then drying it again. Although the paper might become dry and usable, it has lost a lot of its advantages.
It can't be perfectly plain again; for instance, if you write on such paper with ink and then someone pours water on it, I'm 100% sure that the paper can never be the same again after sun-drying it.
Although one may forget the pain, the effects of betrayal will last longer. It may be easy to say, 'I'm sorry, it won't happen again,' but the deed has been done. Whether the other person is able to rectify the damage or not, such a person can never forget the situation, especially when they mingle with other people.
The level of trust they had for people in general will diminish, and one won't tolerate anyone again for fear of getting betrayed or hurt.
Betrayal usually damages good relationships and has lasting negative effects on the victims. That's why the majority prefer to be independent and personal, although they might have friends who are loyal; they tend to keep their things to themselves or write them in a diary instead of opening up to someone who might use it against them in the near future.
However, trust can be rebuilt, but it takes time. One only needs to choose wisely. A group of two people who are loyal and trustworthy is far better than ten people who are incompetent and pessimistic.
Once trust is broken, it becomes a lesson, not a bond, so you take it as a lesson and move on. Everyone is not the same; we just make wrong decisions at times when we think they're right.
Thanks for reading!