Paul Graham is back on The Social Radars with @jesslivingston and @cjoneslevy. This time, they focus on what was happening behind the scenes at Y Combinator in the early years. PG shares how YC grew through word of mouth, what it was like working closely with founders, and how much of it they figured out as they went. Along the way, he recalls stories from the early batches—the advice that stuck, and how small decisions shaped what companies became. He also reflects on how the startup world…