Especially after coming out of a long relationship it can be difficult not to repeat some of the same mistakes with a new partner. In cases where a break-up or divorce became painful or cruel a great deal of unresolved issues maybe left unresolved and can manifest themselves with a new person. Often people are unaware that they are following a pattern unless it is brought to their attention, which can be difficult for your new partner to pinpoint as in most cases they have only witnessed your currently relationship together.
These kinds of unnoticed, but harmful habits can be caused by a variety of incidences in your past. Childhood traumas can force a person to act in a repetitive and destructive manor without their knowledge and in some cases the ex-partner may have brought about this behavior through their actions.
The most important first step is to recognize that you are acting in a certain way and that these actions are harming your current relationship. It is important to let your partner know that you have become aware of this pattern or type of behavior and will now be trying to put an end to it.
Finding out why, the source of your behavior is commonly the next step once you have taken notice of your own actions. In some cases these actions will be triggered by something far in your past, in other cases you may be able to directly link your behavior to your past relationship. While an incident long forgotten may not have taken place during your prior relationship, there is an excellent chance that your ex-partner somehow added to its destructive qualities; either by causing you pain in some way or by neglecting to notice this behavior.

Example of past incident forming destructive behavior; exacerbated by ex:

Elaines father has left her and her mother at an early age and Elaine feels abandoned by him.
As Elaine grows up she becomes interested in boys, but often acts in ways that they find too needy or clingy and become disinterested in her.
With each rejection Elaines fear of abandonment becomes more acute and she continues to act in this undesirable way toward boys and eventually men.
Elaine may enter into a serious relationship, but finds that her fear of abandonment forces her to act in ways that make her boyfriend feel smothered.
Eventually, being unable to identify and correct her behavior, Elaine drives her boyfriend away, which once again, adds to her fear of being abandoned and rejected.
Elaine enters a new relationship and once again begins to become too clingy and desperate; once again Elaine is in danger driving her boyfriend away.

This cycle is very common for both men and women who have lost a parent at an early age, even those who experienced that loss due to a death can still have many of the same feelings. In order to put an end to a pattern like this one a person must be able to recognize that their feelings of desperation are unnecessary; often this is a confidence issue. Once the problem has been recognized a person may begin exploring how it originated and how they begin correcting it. Though this process may not be an easy one, most people find that they are unable to have a happy, healthy relationship while problems such as these continue.

Example of an incident in your prior relationship causing a current pattern of behavior:

Scotts girlfriend was unfaithful to him and lied about it. He found out by discovering this secret from a friend.
When Scott confronted his girlfriend she was unable to explain her motives leaving Scott not only hurt, but confused and questioning whether or not he had done something to make his girlfriend want to hurt him.
When Scott broke it off with his girlfriend none of his new insecurities had been addressed and he is now subconsciously convinced that his exs cheating was a result of his lacking in some way.
Scott begins a new relationship and at first his confidence receives a boost.
After a time Scott becomes convinced that his self proclaimed lacking will drive his current girlfriend to cheat as well.
Scott becomes unreasonably jealous and paranoid, which makes his girlfriend extremely uncomfortable. Scott is now in danger of driving her away.

Another scenario that is common amongst both men and women and a very difficult pattern to break. Though it can be extremely difficult to trust a person when you have been hurt in the past, especially lied to, it is important to start fresh in each new relationship.
Many of the problems that people have in relationships are ones that they continue to bring up time and time again. In some cases people will find themselves at the end of a relationship and be very tempted to blame the failure on their ex, though this is often not the case. It is important to make yourself aware of any shortcomings that you may possess before they force your new relationship into a difficult situation. Though something that your ex did, or an incident in your past, maybe a terrible thing to overcome, it is important for the success of your currently relationship to take that baggage and let it go. Learn to trust your partner, to understand that this person is not the same person as the one who may have hurt you in the past and that above all, you need to trust yourself. Whatever happened in your past, whatever ghosts continue to remind you of your worst fears: let it go. Allow yourself the happiness that you so deserve by recognizing and eliminating those problems until they cannot haunt you ever again.