I shape my life through interesting conversations, so the Castle is in general a pretty life-shaping place for me.
It's pretty great to bounce wild speculative ideas and crazy world models off of the people there and have everyone run with them, critiquing and going further. The Castle's one of those rare environment where all the people can't stand talking about the weather.
Particularly shaping for me are Conrad (who is ridiculously disciplined and rigorous about systematizing decision processes) and Kan (who's so damn direct and problem solving-focused on whatever's in front of him). Assuming you're the kind of person who feels more fed by ideas than food, find a way to meet these people.