Household finances are such a chore for most already, so some fun people have come up with some fun challenges to help you accumulate savings and have fun at the same time! Yippee! Except for one small detail.....if you don't have the money that the challenge requires, then putting that money into savings is going to cause you problems....not fun.
Basically, in order to do anything financial, you have to do the math. Math is the only thing that's going to tell you whether or not you can afford to do something. Ignoring the math will get you into trouble every time. So, sorry to burst your bubble, but unless you think math is fun (which I do, BTW), taking care of your money is not a super fun activity.
It is a super necessary activity though, so let's find ways to get around the math, shall we? By using a spreadsheet or another kind of software that will do the math for you, you can get straight to the fun part of finances, which is seeing your debt disappear, your savings accumulate, and your investments multiply! Yippee (for real this time)!
So, you can't just arbitrarily pick numbers out of thin air when you're making financial decisions. Just because the experts say to save 10%, or whatever, of your money doesn't mean you can afford to do that. Just plug the numbers into your budget software of choice and see what happens.....maybe you can afford to save more than 10%. But you won't know until you do the math.
Same goes for retirement goals. You can't just blindly follow advice, taking the numbers for granted.
Personal finance is just that; personal. The answers will be different for everybody. The good news is, a little math goes a looooong way.