<human>: I'm 26 (male), and she's 20.

My GF and I are both in college. We've been together for a few years now (my longest relationship). We have fun together, hang out a lot, and are generally really good friends. But something is missing. I feel like I should be doing something, or taking on some role that I can't put to words. I know I'm being vague, but it's a very intangible sensation. 

Consider this: It is common to have a dog for a pet now a days, but for me, it feels like a dog should also have a purpose. Maybe he leads around blind people, maybe he tracks things with his nose, etc. But a dog without a purpose feels a little "empty". That's the feeling I'm getting - like I'm in a good situation with her, but I don't really have a purpose.

If this were 70 years ago, I guess I'd be supporting her financially. If this were 7000 years ago, I suppose I'd be spending my time keeping her away from big fucking lions. Logically, I have no idea what role I'm suppose to do now, but that urge to do it is still present.

Can you provide a brief overview of the text?
<bot>: what purpose do I have in a relationship with my gf? Protection? Not really. Support? We're both in college, so that's out. I feel like I don't have a job to do in the relationship.