I used to think this and then it stopped expanding. I have very low needs. Just enough for healthy food and some tennis equipment and I'm happy. It got to the point where I was earning much more than I could justify spending so I decided to change careers for something that optimised for lifestyle over money and now I'm much happier. People think that more money = more happiness, but I'd say that you need more money when you're unhappy. Money buys comfort but not happiness. Ironically when you're happier you need less money.

Personality and habit. For me, being a graduate student for 7 years (masters then PhD) forced me to live simply. Those habits stuck with me through the next decade of good salaries. My spending went up from graduate student poverty, but I still saved and invested 50% to 70% of gross income. Now I probably have more than a lot of peers who started working well before me, but didn't save as much.

To your point, pay yourself first. Set up automatic investments. Find a fiduciary advisor if you must, but it's really not rocket science.

Eh, expenses tend to rise, but for me, it didn't take too many good raises until I had 'enough' pay that an increase in income didn't lead to unlocking supressed spending.

Sure, sometimes I'd be like 'hey toast0, you make good money, you can buy a drink and a snack at the movies'... But I still watch most of the movies I watch at home.

I didn't move all my dining out to the Brazillian Steakhouse or anything. I didn't join NetJets, although I did join NetFlix. Rather than having my own boat and a car on either side, I drive my car onto the public ferry. Ok, I may actually have a car problem, but they all park at home and most of them are inexpensive, and doesn't everyone need a nice 3-row vehicle, a phev for efficiency, a pickup truck, and a minivan for cargo in the rain?

Someone elsewhere suggests banking all of your raises, which works when you can. Even if you're really tight, you can usually bank at least some of your raises. A nice bonus of a high savings rate is people often think in terms of salary replacement... But if you're saving 15-20% of your salary, 80-85% salary replacement matches your spending ... you don't have to shoot for 100% salary replacement.

> your expenses will ALWAYS somewhow expand to your income

No they don't. This may be true for some people but many people do not have this compulsion. I know many people who have zero issues saving money because they are largely satisfied with their lifestyle.

The lifestyle doesn't even have to be austere. You can eat out every night at nice restaurants and rent a very nice place on a budget of a couple hundred thousand per year. There is a natural limit on the amount of money you can spend unless you are blowing it on lots of expensive "stuff" that contributes relatively little to quality of life.

>One thing - your expenses will ALWAYS somewhow expand to your income.

Not necessarily. If the savings deduction comes straight off the paycheque then it doesn't take all that much mental fortitude to pretend what you get is the salary.

Advice I got at an early job: every time you get a raise, set up auto transfer to savings/investment for the net new and keep the same lifestyle (thank you Ramit Sethi)

It's a personality thing. I literally don't need anything and hate spending money and am miserly as a hobby.