Some things, like your next job, might happen as the direct result of one meeting. Here I am, here's my resume, okay, you're hired.
But most of the time, that's not the way it works.
You meet someone. You do a small project. You write an article. It leads to another meeting. You do a slightly bigger project for someone else. You make a short film. That leads to a speaking gig. Which leads to an consulting contract. And then you get the gig.
How many hops does the ball take before it lands where you're hoping it will?
If you're walking around with a quid pro quo mindset, giving only enough to get what you need right now, and walking away from anyone or anything that isn't the destination—not only are you eliminating all the possible multi-hop options, you're probably not having as much as fun or contributing as much as you could either.