If they like the same things as you, it's easier but folks grow out of interests sometimes and want to explore other things. This can be a problem, or not, depending on the couple.
They should be sympathetic to your interests and allow you the time to stay in touch with it if they aren't in to it themselves, and you for them. But if your interest is a way of life thing like BB, your partner would have to be ok with some long time changes for it to work.
Those folks who have nothing in commmon get their arses put through the ringer when the serious life and death shit kicks in. If they respect each other they should be able to shift things to a new level. If not, ever onward and upward I guess.
I look at a lot of my Dad's mates who married beautiful women bitching now they dont have a thought in their head and are a pain to live with. Not wasting any sympathy on them. It just turned out lonely for them in the long run and for their partners. How lonely to have a guy who built a life around you and your kids who cant stand anything you have to say.
I have no answers. If it works its a wonderful thing, but shit happens and people die or have a personality transplant fueled by dickhead friends or aging and it can all hit the fan in a minute. Relationships are under attack from reality from the moment they form. If they can take the hits together and pull their energies in the same direction and not wear each other out with crap its on.
Deicide, that girl sounds to me like she hasnt figured that stuff out yet.
Give it time.
