I'd like to put a stake into the idea that just being more "responsible" about expenses leads to a comfortable retirement without an income that is well over the median.
This has an echo to when I was a teenager, encouraged to save every penny I earned for college. I'm glad I didn't, because what I could earn and save was literally spit in the wind compared to college expenses. It did not pay for even one quarter of room and board, much less tuition. My family had no money, I worked evenings and weekends from the age I could legally work to when I flew to college. I wish I'd spent every penny I earned (and wish more that I'd just worked less...working some had value in pocket money that let me participate in stuff my wealthier friends took for granted) because I couldn't get those hours of my life back, and the saving made absolutely no difference in my odds of paying for college.
I say this as someone who hit the genetic lottery on intelligence, getting a nearly free ride at a top university, graduating only 20k in debt in 1988. Someone who is looking at early retirement because of both good fortune and good decisions, but the fortune weighs higher. I've worked minimum wage, hell I've worked less than minimum wage, I've done it as an adult full-time with overtime and with the BS part-time hours that are typical these days. I know what it could buy in 1990, and it's a hell of a lot more than it buys now. I've also worked an entry level office job for years, at steady income that was about poverty level, but just being steady makes a difference.
Here's my analysis below the fold. Think about it before you judge anybody for how they spend their money. You must take care of three priorities first before saving for retirement makes sense.