Every time I've tried to build some elaborate "knowledge garden", it always devolves into post-it notes and random e-mails to myself. Very interested in using something that lets that become my starting point instead of my end result in defeat.
It's also invaluable to be able to stand in front of a group of people (whether VCs, the press, other startups) and be able to clearly communicate what your startup does.
Viewing Demo Day as a tool that's only useful if you're fundraising on the back of it is incredibly shortsighted.
Are you ready to not sleep for god knows how long? Have you thought about how you'll make money until your start up actually makes money? Do you have hundreds of connections? Because in reality that is how you grow - it's all about who you know and how you leverage those relationships.
Best of luck to you - been there and it's a long, but exhilarating ride.