I let go. The envelope dropped with a thud, the lid banged shut and I felt a sudden panic.

I could see myself defacing federal property. I envisioned a scene where I'm pleading with the postmaster to return my envelope. Give it back! It was a mistake! I didn't mean to mail it!

The envelope contained my application to a graduate school teaching program. At an age when I thought classes, tests and grades were behind me, I'm changing course and trying a new career. It feels a bit like stepping off a cliff. After 15 years as a working journalist, I've decided to become a teacher.

And so I found myself a couple months ago sitting in a room with two sharp No. 2 pencils, an empty answer sheet and about 40 fellow test-takers who looked as if they could be my children.

The urge to run was strong. My confidence waned as I sat amidst a crowd of college kids who have never typed a term paper on a manual typewriter using carbon paper and White Out. .

In calm moments I remind myself that 46 years of living have given me practical experiences, increased patience and I hope a wisdom that comes only with time. My professional life has given me insights on working with others, managing time and keeping the world in perspective.

But faced with my first standardized test in 17 years, all I could think was "I must be the only woman in this room who has been through childbirth!" As a middle-aged baby-boomer, I'm at the point where I'm too young to be old, but too old to be young.

I well remember that golden time of life when all things seemed possible. It was a heady time of youthful enthusiasm when the world was filled with endless opportunities ripe for my picking.

My own children are in this endless-opportunity age. "Mom," they say. "I'm going to be a police officer or a neurophysiologist or an FBI agent or...or...or..." I hope the stage lasts for a very long time for them.

The world still seems filled with opportunity to me, but experience and reality have tempered the possibilities. I know that certain options have passed me by.

I will never be a concert pianist, an Olympic figure skater or an astronaut. I won't be the person who discovers that elusive cure for cancer. But something tells me I can be an elementary school teacher. Something tells me that knowledge I already possess can be passed along and I can find a niche in the world of education. Something tells me it's not too late to take a new path and find a new passion.