When going away on conventions / seminars / workshops you (hopefully) learn something new - which is great - and probably why you went there in the first place. But maybe the most valuable thing you get at an event like this is the people you get to know. People from all walks of life, from all over the world. Likeminded people. People eager to learn, eager to grow.
Over time it's impossible to stay connected to everyone you meet, but through social media we can remain in each others awarenesses. By remaining in the Facebook groups that often are created for these events you are still connected to that tribe over time.
A large part of my international network has come from these events and I'm still in touch - one way or another - with many of the people I got to know during a couple of events over a decade ago.