I remember about 3 years ago when I was running a VPS hosting company, which was later sold. There was an issue with the virtualization technology causing all VPS to lose connectivity intermittently, I was working with the control panel developers and other specialists to make everything right again, it took 72 hours to fully fix and bring everything back up, a lot of heartache, headaches and coffee!
But seriously, you need absolute dedication for start-up businesses as they can crash overnight if you don't pay attention. I have in the past, employed an outsourcing company just to cover the evening hours so I could at least relax with the family during the evening hours. Obviously I was still available 24/7 via phone emails and such but the front of it all went to the outsourcing company.
I don't really like outsourcing but when you have a demanding wife and 2 kids, it's kinda hard to be everywhere at once!