Editor's note: The following article was originally published on Sept. 13, 2001 -- 48 hours after the worst-ever act of terrorism on U.S. soil. We're republishing it here, unedited, as a reminder of what's really important in life.

In the daily bustle, it is easy to forget how fortunate you are if you have health, family, friends, food, and shelter. If you have these essentials, you're among a small minority in the world. A majority of people on the planet lack at least one of the above in adequate amounts. A majority of the 6 billion people on Earth live not only lacking food, shelter, or health, but a majority live in extreme poverty for their entire lives. 

Most of us reading this column possess not only shelter, adequate food, and generally (I hope for all of us) good health, but we also have disposable income, a true rarity in the world. We have income to invest in stocks for an even better future, or to invest in leisure time, or to invest in others.

What matters most in life?

Living honestly with yourself and with others; appreciating and being thankful for what you have; helping others when you can; being positive rather than negative; being part of a solution rather than part of a problem; working to improve the world and leave it a little better than you found it.

When you remember what's most important, it makes life seem relatively simple. Personal worries should be few if you have health, shelter, food, others you care about, and freedom along with opportunity, which our country provides in unprecedented amounts.

We've shared this sentiment here at the Fool many times the past five years, always on normal, uneventful days. Given the senselessness of this week, this simple message -- that we should always appreciate life in peaceful and simple ways -- seems sadder than ever, but more appropriate than ever.

If you care to give to others in light of this week's tragedy, please see The Motley Fool's report on what you can do.