If it is for an article then maybe a better enquiry would be how much debt were you in by the decade?
In my 20s: mortgage, credit card, overdraft, all to as much as they would carry. Both worked NMW jobs and paid off minimal amounts every month. Lived very much hand to mouth. Had a mortgage as it was cheaper than rent!
In my 30s: I'd got rid of the overdraft and was working through the credit cards; both went to Uni, so lost 8 years worth of salary in total. Sold the flat, paid off the credit cards, saved what was left
In my 40s: rented and both worked our socks off, now had professional jobs, had a salary rather than a weekly wage. Saved and saved and saved. We'd got used to only having one wage, that was helpful!
In my 50s: free of debt. Own the house and have savings, working towards pensions - only started that in our 50s.
We don't have kids. We don't have a lavish lifestyle. Both are fairly miserly when it comes to spending on holidays, cars, phones etc.
Does that satisfy your curiosity/editor?