A business partnership is a relationship. It's certainly not a romantic relationship, but it can be just as intense and emotional as a romantic relationship.

No one is suggesting that potential business partners take each other out to the movies. But it's a good idea that they spend a lot of time together and get to know each other well before jumping into a partnership together.

That's why the analogy works. You don't meet someone at a party and marry them the next day. You shouldn't meet someone at an event and make them your co-founder immediately either.