It's not easy to move on once we're lied to, or betrayed. It's hard to not feel hurt when you're ditched or sad when you feel that you have been let down. It's difficult to move on from something that left you with those ill feelings. But, even if you never get the apology you're looking for, you need to take a deep breath and forgive whomever harmed you for whatever it is they've done to you, because it means taking responsibility for that other persons actions, and showing yourself that you will never harbor those ill feelings onto another human being.
Being able to forgive is something that takes time and it takes patience, which unfortunately patience is hard to come by these days. We are so used to getting what we want when we want it and when we don't practice what it means to wait. So when people get into arguments or feel like they need an apology, sometimes the issue becomes greater than it needs to be because while we are impatiently waiting for an apology or when we are waiting to be the one to apologize, those ill feelings begin to grow stronger and stronger just because you didn't get what you wanted when you wanted it.
When you are able to forgive someone, you own responsibility. You are implying that you understand what that person did to you was wrong, and that you will sake the initiative to not make anyone else feel the way that you felt after that happened to you. Sure, you can hold a grudge, you can ignore that person, and you can pretend that their existence in your life was nothing more than mediocre. But, that's not true, and all you're trying to do is lie to yourself to justify that this person did you wrong and that is not ok. And it's not ok, it's not ok to be betrayed or lied to, but it's also not ok to walk around with hate in your heart. When you forgive someone, that doesn't mean you are condoning what they had done, it means that you are the bigger person and you will not let their actions get the best of you, because you're better than that. Be better than that.
Life would be easier if we could just forget the bad things and just reminisce in the good, but that's not how life works. The bad things are what make us who we are; they make us the kind of people we like to see when we look in the mirror. It builds character and it makes us strong. Forgiveness does not make you weak. You are not admitted defeat or admitted that you are in the wrong. Forgiveness is like ending a chapter in your book, when you are finally done writing that chapter the next one begins. And when you look back, you can re-read that chapter, see how you've grown, and see how strong you were.