I totally get the desire to live alone, but I never have because having roommates/cohabitation always seemed like such an obvious economic decision compared to other ways to reduce living expenses.
The Onion put out a video[1] in 2009 about an economic recovery plan that amounted to boyfriends finally agreeing to move in together with their girlfriends. I've spent a lot of time researching the housing market and macroeconomic reasons for its current distortion from historical norms. That video often pops into my mind when I do. The overall housing stock in the US has more than kept pace with the growth in population, but the reduction of household size and related growth in housing space per person has created a huge amount of incremental demand.
I don't think those are purely bad trends. My parents' generation paired off young and quickly, and the long term effects are easy enough to pick out in divorce statistics. But I do have to wonder how much of the economic woes 20-40 year olds face right now might be alleviated if the pendulum swung back a little in that direction.