i am posting this example in hopes to inspire those who aren’t investing some of their money to start today
lets say you are 18 and going to college. you toss $2000 into an ira making 12% returns.
in 42 years (that makes you 60 incase you suck at math) that will be $291,807
not bad, but what happens if you can toss just $100 a month at it?
it becomes $1,587,906
thats better than not bad for not a lot of money invested.
most people here aren’t 18 though 
lets say you a 25, and maybe have 5k to start with. that 5k will end up at $263,998 in 35 years. now i assume you have a little more loot to spend, so lets say you toss 3000 a year at that (thats less than what i spend on beer every week).
you will end up with $1,714,387.
now take that and make a conservative 6% return per year, and you will have an income of $102,863.
think about how much you would have if you tossed a little more in. maybe employer matching, or by taking advantage of a HSA.
here is a compound interest calculator to play with
http://www.moneychimp.com/calculator/compound_interest_calculator.htm
“The most powerful force in the universe is compound interest”
-Albert Einstein