A central feature of marriage is the ability and willingness to give and share. Some people find that difficult, and focus mostly on their own needs and wishes. Dr Elinor Greenberg sets out the main characteristics of narcissism, and how you can identify narcissistic tendencies.
To make things simple, we divide this beahvior into three categories and reflect on each. They are: 1) selfish, 2) mildly narcissistic, 3) acutely narcissistic.
The core of dating is commencing a process through which you become increasingly absorbed in a single person. At the beginning of the process, you are understandably being selfish. However, for the dating process to achieve its purpose it must transition from a continual focus on your own interest to a growing attachment to the other person.