Just think of it as taking "Release early" and "Iterate" to the next level. In this case, your iteration involved executing on an idea, building a business out of it, then selling. You've been there, done that. Now you're equipped with lessons you've learned from your first iteration, and are ready to start your next. And you're not even 30!

It's certainly a better problem than, say, wondering if you can actually build something that will allow you to quit your boring day job.

Good luck!