Would recommend going through a divorce while building a startup for the ultimate entrepreneurial "nightmare mode". Great for building a tough skin after it's all over. Some founders come back home to an unconditionally supportive partner, others come back to a bunch of legal paperwork.
Nowadays I prefer to rent a single room in a shared house. Thats really all the space I require to be happy. my futon, my desk, my electric piano, a workbench, a couple bookshelves and my cat.
How is day to day happiness? I'm only 29 and I want to live like that forever but I can't imagine it's conducive to an active sex life. (Again, I'm young, hopefully testosterone tapers off substantially as the years go on.)