I learned about living below my means, investing etc. in my early 30's (mid-50's now). At the time, a financial services company had a slogan "Freedom 55". I remember investigating it and to succeed I would have had to save about a third of my income. Seemed too hard and I was afraid of what my life would look like with all the wasteful spending gone. So I didn't even try. I didn't think I could do it.
Then 5 years ago I found this website by chance. I was saving 10-15% of my income, had no credit card debt but was still worried about money. So I started applying some of the techniques: tracking spending, investigating my spending, working up to a higher savings rate, letting go of some stuff etc. And it was and is fine.
Also, in my 30's I was interested in having a career and maybe moving up to something more challenging. However, a mental illness got the better of me and having more responsibility would not have worked for me.