Even compound interest doesn't work that fast. From some napkin calculations you'd still be starting off packing away like $2-3k/mo from the start of your career at an interest rate of 5% and an inflation of deposits of 3% to pull it off. For reference, the average YEARLY family income in the 60s was in the $5k range.

The stock market averaged about 7% annually during that period (and it was a slow period. the average for most periods is roughly 10% annually).

That still has you packing away about $1k/mo to start with for 10%. Again, that's 2 months or so worth of income for an average person in the 60s.

I'm sure he wasn't putting that much away when he first started, but as he made more, he put away more into his late 30s/40s. There was also a big real estate boom so some of his rental properties probably beat the stock market by a bit during some of that time. Definitely an above average job as well, but not an amazing one. He probably made the equivalent of about 100k today for most of his career (once he was established, not at the start), like many small town lawyers.

That was including growing the deposits at a rate of 2-3%, which ends with approximately $3k/mo at the end.

Anyways, him being a lawyer pretty much answers the issue. You don't usually call any professional job a 'normal job', and that clears it up. It's pretty likely that even then it took some high risk/high reward investments or some lucky real estate buys in the meantime to drive it up that much.

Which is not to disparage the achievement of saving $5mil pre-retirement (or even at retirement) age. It takes above average fiscal discipline and money management to do that even with above average income.

My original point was just that a compound interest savings account isn't that amazing. You have to do more than just sock some money into an account to pull it off.