Means to an End
The surface of many different things can seem to be the same, but they can be very dissimilar underneath. It is the same with two people who are dating, and it can take a great deal of time for them to discover. They might both desire to achieve the same goals in life, but the means to an end to get them might be very different. One of them could be willing to work hard and wait years, but the other person might be more apt to take dangerous or illegal short cuts to reach the goal.
Being able to share goals is important for a long term relationship, but those who are unable to agree on the methods of achieving them will often end up arguing. Each of them might feel their partner is uncooperative, or they could be disappointed in their moral outlook. It could cause a rift between the two, and healing it might only be possible if one of them is willing to make a change in their basic personality.
For those who believe compromise is important, finding ways to come closer to their partner could help the situation. If the other person is also willing to give in and find middle ground, the pair might be able to function in a relationship lasting years. As long as neither of them returns to their previous stand on the issues, they could form a lifelong relationship and achieve their goals.
While it is important for two people attempting to form a good relationship to have the same goals, it can matter even more that they agree on how to get where they want to go. Couples willing to compromise with each other to find acceptable ways to achieve their dreams will have a better shot at staying together.