SXSW Interactive is a "choose your own adventure" type of conference. Of the 10K+ attendees, everyone walks away with their own unique SXSW experience. At times there are no less than 10 panels / talks / workshops happening concurrently, ranging across the entire spectrum of web-related disciplines. When you first glance at the schedule, you get this overwhelming feeling that there's just too much to do and too little time to absorb it all. You feel a sort-of anxiety as you worry you'll miss something big which everyone will be talking about after the fact.
After your first day, you start to get the hang of things. You've attended some interesting talks and you start to feel this re-invigoration about the web and your place within it all. Sure, you've surfed the web countless times before, read blogs, viewed vlogs, etc.. but you start to feel a special sort of energy which can only exist once you put all these intelligent web-citizens together under one roof.
You meet people at random. Strangers, which quickly become familiar to you as you realize how much the web gives you in common. You may have never heard of company XYZ, but you appreciate the fact that everyone has their own place on the web. When the common "What do you do?" question comes up, you start answering more precisely, which you couldn't do back home, because the people here "get it". You're no longer an "Internet person" but instead a master of your web discipline(s), which is nice to explain without the usual blank stares in response.
Following the presentations throughout the day, the after-parties are another way to meet like-minded people. It's a chance for the more reserved individuals to come out of their shells (be it with or without the help of a little liquid courage). Who could judge you for who you are when you attend something like a geeky beach party hosted by a web-hosting company or karaoke party hosted by a design company?
Despite all the positive points, however, no conference of such magnitude is free of problems. Certain panels thinly guise themselves as a general discussion but end up more as a promotional effort. Commercial presence is ever apparent as targeting the web crowd could inevitably turn a profit. Some other discussions feel more like a summary of what we already know as opposed to a step into unchartered territory. Some panelists can, at times, not agree on the discussion's topic which unfortunately results in a back-and-forth with little overall progress made. As a result, you become accustomed to leaving a presentation which isn't going your way. You cut your losses and slide into another presentation which quickly rectifies the problem.
At the end of the day, during various down times, or maybe only once you get back to your normal life, you absorb and reflect on the information overload which you've been a part of. This is where things come together. You look at routine portions of your web work a little differently now. You make small, seemingly insignificant changes to the way you do things, yet in fact, these same changes could have taken you months to uncover or may never have happened at all. This is the underlying value of SXSW. This is why people come to SXSW.