You sound like an old co-founder of mine. When he latched onto something, be it developing code or burning a DVD collection, he went all in, and dropped everything else for extended periods of time. While I do this at times as well, I think it's best to live a balanced lifestyle (http://www.pathways.cu.edu.eg/subpages/training_courses/Well...). I believe you can have a family and take vacations and still build a killer startup. Look at famous people like Bill Gates, Warren Buffet, the CEOs of many fortune 500 companies - many are married with kids - and yet still very successful in business.