Let me also clarify that I *could* retire a good bit younger, but that would require changing my lifestyle, which I don't plan to do.
I'm also a busy body and can't imagine NOT doing something, so instead of hobbies that cost money, I prefer to keep myself busy making money.
Kids/Grandkids/Illness/disability could change my plans, but based on my investments and projections, I could quit working at 75 and maintain my current lifestyle.