A good-sized retirement isn't just for fun. It's to work against inflation and maintain financial security / independence, it's to prepare for potential catastrophes, and it's also to prepare for your declining years.

Actuarial tables show if you make it to age 40 you have a very high likelihood of making it to 80 or 90. Statistics show that the last decade of your life - thanks to health care needs or assisted living necessities - is often more expensive than any other decade of your life.

That's absolutely important to plan for in your 20's and 30's when you have the time (and energy) to make a difference.