“Wake up before your kids”? Hah! You obviously don’t have kids. It’s not uncommon for mine to wake up at 5:30am.
I love how you’re pointing out that it’s the mindset more than anything that’s important. But you seem to be using that as an excuse to ignore a lot of other really good advice.
Having a dedicated office space, keeping regular work hours, making to-do lists, getting out of your pyjamas — these are all things that help some people get into the “work first” mindset that you talk about. Just because you don’t need them to be productive, doesn't mean they are bad pieces of advice for others who may definitely need more structure to achieve that mindset.