I really hope someone young reads this and thinks about it. I think the average TF member is frankly too old to do anything about it. By the time you are in your 50's you're there or you are not.
Your points are well made and excellent advice to those younger. But I wouldn't totally ignore the changes possible in one's 50's. Go into retirement mode of thinking early, imagining living only off your retirement income. Downsize to the house, condo, or apartment that would require and save the difference. Many have enough equity in a home to buy a condo and have no mortgage and no house payments. You had 3000 square feet for you, spouse and two kids. Now 800 will suffice with kids gone. The difference in interest and upkeep could be over $100,000 in 15 years. Forego trading cars. A couple with two cars and 50 years old might have a habit of trading every 4 years. That means 6 cars before 65. Trade every 8 years and that is 2 cars. Just saved $80,000 or more. Rethink major expenditures. Eat at home rather than out five nights a week. Eating habits and cutting down on restaurants can easily save a couple $50 per week. That's $2500 per year, $37,500 in 15 years. Even if you just have 5 or 8 years of the more frugal lifestyle it can mean a lot at retirement.