E.g. I want to buy a Tesla and I don't have the money. I say to myself : "Now it's not the time." instead of "Let's save some money!".
If you have millions and you want to buy 10 cars, then I think you have a problem with your ego.
You have your basic expenses you need to live (food, shelter, water), which cost most people at least tens of thousands per year.
If you live miserably only allowing money out to expense those needs, you're still only saving tens of thousands.
You have a lot more ability to increase money coming in than money going out.
I think this is the point OP's father was trying to make. Don't get stuck in a loop of allowing your employer to pay you $xx,xxx (or $1xx,xxx) for decades and restrict yourself for your whole life just to retire old and live an average lifestyle. Take control of your life and control your success.