I am trying to get into the start-up scene (or at least it is a consideration). Recently a friend came up with (what I consider) to be a decent idea for a start-up. Working on that idea and fleshing on the business and technical aspects, I forgot how good it feels to be completely absorbed by something and love every minute of it. Definitely will keep up with the threads
Definitely pursue what you love doing, but I would only recommend starting a new company from scratch if you have some industry expertise, as well as some savings or other means to support yourself for a year or more.
If you want the startup vibe, but want a much more stable life, look for a startup with 10-20 employees, and profits.
And don't rule out getting a "normal" software job. Market rates, regular paycheck every 2 weeks, bigger team, plenty of resources, and you still have the potential to find a "startup-y" culture and some fun projects if you look around enough. Plus you can stash half your salary to fund a war chest for later entrepreneurship.