Oh, I’ll play! (I basically spend about one third of my work life dreaming of retiring). I would be comfortable retiring at 50 with $10M in investments. At a 4% return, that gives you an annual ‘salary’ of $400,000- about $275,00 after taxes (gross estimations).
I have a horse in full care in a mid-cost of living area and we show at A/AA shows once to twice a month. I spend between $80,000 to 100,000 annually on him (God that is terrifying to see in print). That would leave around $175,00 for other costs after that, which would accommodate my non horsey life (bills, mortage, car, etc) with a cushion. I agree with other posters that health care/ insurance could be a large expense which I have not researched and could definitely affect the calculus. I also don’t live in New York or California or another expensive place, so that would likely change the calculation as well.
As an aside, there are ongoing debates in the financial community as to whether that 4% withdrawal rate is still feasible and that perhaps 3% is more reasonable which would change this whole answer.
I also agree that while I dream of retiring, actually doing it would be terrifying due to financial/ market concerns.