Weinberg's seminal prediction of the cosmological constant relied on a provisional method for regulating eternal inflation. I will show that a modern regulator, the causal patch, improves agreement with observation, removes many limiting assumptions, and yields additional powerful results. Without assuming necessary conditions for observers such as galaxies or entropy production, the causal patch measure predicts the coincidence of vacuum energy and present matter density. Their common scale, and thus the enormous size of the visible universe, originates in the number of metastable vacua in the landscape.