His life and his interests and hobbies always changed depending on his main friends or love interests.
I always felt like neither of the narcissists I married had their own personalities. The first narcissist was more covert–he was not so outwardly aggressive with his narcissistic tendencies–and the other was more overt–there was no missing his aggression and rage. However, neither one of them stood alone as a person with a stable identity and interests. This is common with narcissists because they mirror and mimic their current targets. It’s how narcissists draw in their prey, but it’s also because narcissists are so devoid of passion for anything.
Narcissists have multiple faces. Now, we all adapt our conversation and behavior to match our situations. For example, you might discuss different topics with different friends depending on your common interests, you might be sillier with one group of friends or more serious with relatives, etc…, but you remain the same person with a variety of interests. However, narcissists pick and choose hobbies and values on a whim, and never with any sincerity. They become completely different people without a thought.