But I think you're right in your first comment about being passionate about the idea! The thing is, you don't get a salary from day one or maybe even year one (as compared to, for example, to building a VC-funded startup or working somewhere) and so you need to find the energy and motivation from something else, and "passion" fits very well with this "something else."

As I recently wrote in one of the latest newsletters (you'll find it on MicroFounder, called "keep going"):

"It can be easy to abandon your project as soon as you launch and don’t see instant results – be it visitors or paying customers – but I’ve been looking closely how microfounders build their startups for the last 3+ years and I’ve almost never seen a real overnight success."