I think it becomes such an ingrained habit, if it has all been accrued over many years, by hard work coupled with frugal habits
I haven't read any further than this early response, because I relate to it so much.
I am only now, at 70, learning to spend my money. My late husband and I had to be very frugal for the first couple of decades of our lives, for reasons that came one after another. Two periods where we bought homes that needed a big mortgage (I'm in the south east) when interests rates were high, then when we had the children, and I wanted to be home with them for the early years, etc etc.
It became so ingrained (and of course there was saving for our retirement) that I had trouble spending money on anything not needed, and was always looking for the best bargains.
He died before he could get the benefit of retirement or spend the money he'd saved for it, and I soon discovered that I didn't need to use those savings. The various pensions, especially when I got the state pension too, are more then enough for me to live on.
So in the past few years I've been helping my kids in various ways. I pay for a UK holiday for us all reach year, I subsidise nursery costs etc and I've stepped in with decent amounts at other times of need.
But I still find it hugely difficult to spend on myself, apart from on holidays. It's so ingrained.
But it's difficult to know what you'll need and when you'll need it. If I need care, I want it to be somewhere decent. But I also don't want everything my DH and I saved, disappearing that way, as my mum's and MIL's did. But without a crystal ball, you don't know when to start spending it.