Why not? I can imagine that there's only one problem with that: You don't have enough money to support yourself so that your startup needs to be done ASAP. Then

Why not? I can imagine that there's only one problem with that: You don't have enough money to support yourself so that your startup needs to be done ASAP. Then I would recommend to do some contracting work. This has two nice effects: First, it gives you money to let you support your startup in the long run. Second: It makes you more productive, because the time you have available to work on a startup is reduced. This constraint makes you focus more on the stuff that really needs to be done. Oh and third: Every idea needs time to evolve. I mean, real time. Not time you invest, but time doing something different. Just waiting-time. I believe, if you cannot afford taking a break from your startup, your startup has a conceptual problem.