You know the old adage that money doesn’t grow on trees: We can’t just pluck a few bills off the branches and spend frivolously, knowing more cash will grow right back. For most of us, money is a limited resource that takes us effort to earn. Once we earn it, it can take us even more effort to save it. So if you’ve been seeking answers to the question, “How much money should I have saved?” the response depends heavily on how old you are and what you’re saving for.