Your wife has been studying frugal and eco tips for years. Go ask her.
As usual, she knows everything.👌 

 I think this is about more than just saving - saving and not having expendable expenses is good. But I think this is about financial freedom trough investing as much as you can as early as you can. Boy, I wish I wasn’t an idiot back in the day. 

 This 👆

Also in my opinion, saving money is general. It is spending less then you earn.

Frugality and minimalism are both type of lifestyle that shows certain behaviors towards money.

But at the end, I think you want independence, security, freedom and these are great ways to live a fulfilling life but still progress towards these goals.