Taming The Fear Of The Wild.
Emigrant Wilderness, CA 2007
It could be because of that experience as a teenager that in my 20's strange sounds outside my tent got my heart racing.

Eventually, after many solo trips I have been able to tame the fear of the wild, primarily through meditation and contemplation during the actual trips.  I think that by confronting the fear head on allowed me to see what it was and to acknowledge that in all reality there was nothing to be afraid of (at least 99% of the time). 

I was able to make peace with the fact that yes, there always is a chance that something dangerous could happen - after all, I am alone in the wilderness.

In effect I was able to make peace with the fear, and now I consistently have a wonderful time on my solo treks.  There are a few moments here and there where the mind's "what if's" are generated, but I never have sleepless nights anymore.
Day 3:  9000' ft elevation, alone, deep in the wilderness,  2 days hike from the nearest road.
1st nights campsite was in a beautiful meadow with alpenglow on the peaks above.
Solo backpacking is a rare joy that few people ever get to experience.  That is, it's a joy if you can tame your fear, otherwise it might become a nightmare.

Backpacking in the wilderness with a group is a peice of cake.  There is something about being with other people that gives you a false sense of security when you're in the backcountry.

Once you're alone in the sticks everything changes and you wonder "is that a mountain lion back in the trees?" or, in the middle of the night in your tent you query, "what's that noise? Could there be a bear out there??"

The fear factor definately increases in magnitude when you're alone.
For several years during the 90's I took solo backpacking trips and had some trouble, mostly at night and mostly for naught.
2nd day.  Hiking up the valley toward the high country.
The irrational fear (ok fear in the wild is somewhat rational as people do get their tents invaded by bears, though extremely infrequently)  I experienced probably originated with one of my first full fledged backpacking trips when I was 15.

My friends and I were camped near Comanche Peak, Colorado and Diana Dannemann and I went to fetch water which was a good 1/4 to 1/2 mile from camp.  It was after sunset and very dark (not a smart plan) and we were a couple hundred yards into the forest when suddenly a loud and deep animal sound emerged from perhaps 50 yards in front of us in the ether.

I turned around and ran so fast that I must have broken the 100 meter dash time for boys my age.  Diana was left behind, but not too far behind because she was running just as hard as I was.

When we got back to camp I think everybody laughed but we were scared. I didn't know if it was a bear or and elk, or what, and I'll never know.
2nd day.  Continuing up the valley with the enormous granite peaks emerging.
2nd day.  Finally at the top of the pass, 10,00ft.  In the distance is the northern border of Yosemite National Park where thunderclouds are pounding the peaks with rain and lightening. 

As soon as I began descending into the valley below the rain starting falling.

High altitude above the tree line is the worst place on earth to be during a thunderstorm.

By the time I reached the bottom of the valley (shown above) I realized that I might be in trouble.  I kicked it into high gear and was practically jogging with my heavy pack. (Once I got to the bottom of the valley, I headed to the right behind the red rocks. Tree's were supposed to appear again in a couple miles where I was thinking I could take cover)
2nd day.  After fast hiking several miles from the pass there was still no cover to be had and the lightning clouds were getting closer.  I picked up my pace and started praying. Thunder was exploding behind me within a mile.

I entered an area full of large boulders and started heading towards them thinking at least I might get some cover next to a large boulder.

Then it appeared, sactuary.  A shallow cave formed by the boulders (SHOWN ABOVE).  I immediately jumped into it and....
....within 1 minute...
....the onslought overtook me.  Lightning strikes went off all around me as heavy rain and hail fell.
After the storm passed the wildflowers and grass were covered in hail.  I decided to camp here for the night.
Day 3:  The rain and clouds cleared by 9AM.  The image above was the approach to Emigrant Lake, very beautiful.
Day 3:  The best campsite ever.  Buck Lakes. As a bonus it was warm enough to swim.

The next day I hiked 18 miles back to my car - my personal record with a heavy pack.