Let me clarify, no I don't think interests should be the bedrock of any relationship, but as far as happiness is concerned it is near the top.
I've been in a relationship where we have nothing in common, and we couldn't even agree on what movie to see at a theater for example. It sucked and was frankly miserable.
You know how much joy it is to find someone who likes and does the same things you do? That atheist I was dating earlier in the year, folks around here said I should have broken it off, man we were just killing it. The fact we could share the same things and not even come up with a disagreement was wonderful.
But you think those commonalities are going to be the glue when life throws major curveballs to knock down the milk bottles? Nope, and that's where I'll agree.
The strength of the relationship through those struggles, comes down to communication, commitment and trust. Get rid of one of those and kiss it goodbye.
But see Tri this is why marriage is a crazy endeavor outside of Church atleast.
You are exactly right, what will happen in 10, 20 or 30 years? I have no idea, and neither do they. Are they going to be ready for the windfalls that can impact their relationship?
Then really nobody should get married with that kind of reasoning.