Yes there are. My brother in law sold his startup and is sufficiently retired while raising my nephews. Not a common case, by any stretch of the imagination, but it's not zero.
I used my words carefully when I said "retire by merely 'saving and not over spending'".
Your brother in law did not merely save and not over spend, he built a business and sold it for a large payout.
I used my words carefully when I said "retire by merely 'saving and not over spending'".
Your brother in law did not merely save and not over spend, he built a business and sold it for a large payout.