It's not much of a spoiler to say that in Season 2 of Dawson's Creek, Joey leaves Dawson in order to "find herself". More about that later, but it reminds me of an exchange from The Thin Blue Line:
"It's an alternative culture now, Sir. People are asking questions. They want to know who they are."
"Then they should damn well look at their passports."
To the idea that a person is trying to find themselves, there are several tempting responses:
- Go look in a mirror. There you are.
- Look around. You're right here.
- Check your driver's license. It's supposed to have a current address.
There's some validity to the idea of a person needing to find themselves, in that a person can be in a situation so overbearing that no decision that the person makes is ever their own; it's highly dubious, though, that people ever really fall into this. There's an idea that some people have that they can be so much in love with someone else that they themselves disappear. If this were ever to really be true, I suspect the relationship between the people would be more like a dog and its master than a relationship between two people.
But even so, I don't know that the one person would be truly subsumed in the other. To use the names from Dawson's creek (since they sound better than "Person A" and "Person B"), if all of Joey's interests were actually Dawson's interests, it means that the energy to enjoy them came mainly from Dawson. (Interest, like all good things, always requires energy. As Chesterton observed, "There is no such thing on earth as an uninteresting subject; the only thing that can exist is an uninterested person.") The nature of friendship is to look together at something else; even if it starts by Dawson providing all of the energy, the friendship could never last if Joey couldn't look at them herself. In the worst case, she would gain an appreciation of Dawson's interests that she could share with someone else. The great thing about knowledge is that it doesn't lose anything by being borrowed.