Expectation is the root of all disappointment.
State it in mind.
Attachment is the root of all suffering.
Plant it deeply in mind, so deep that it become one kind of principle of mind.
And last but not least
You either get bitter or you get better. It's that simple. You either take what has been to you and allow it to make you a better person, or you allow it to tear you down. The choice does not belong to fate, it belongs to you.
Always choose the first. Use both logic and feeling any human have, wisely. Consider any consequences you have to deal with in both short and long term period. Remember that blaming other people or situation will never solve any problem. It's you who is responsible for every of your own decision in life.
I've found out more as I grow older, that real life's not as simple as black and white, good and evil, it's in fact quite complicated. Decisions sometimes are the result of splitting the differences after negotiating between two opposite poles...