Then as stated in the article, only work on the side project for an hour a day over 365 days. Time is on your side and it's OK if it takes a year to get to an MVP. Look at Stardew Valley, for example.
> better yet you will need a very easy day job that doesn't use up the bulk of your daily creativity and problem solving stamina. Yes, it is a finite resource.
This is a fair point. That being said you can always focus on side projects that aren't related to the day job (and in some cases that might have to be the case contractually.) For example I'm a DevOp by day, but my business is moving into VR.