The frontal lobe of your brain is the area where cause and effect are ironed out. The younger you are, the less developed this sense is. Consequently, you get a five year old who thinks that if he jumps off the top of the monkey bars, he will float safely to the ground. Actually, he doesn't even think past, "I am gonna jump off the bars.... WEEEEEEEEE!"
The underdevelopment of the frontal lobe even explains why I, while in 5th grade, gave a letter to a girl in my class that proclaimed my "love" and asked the following question:
a- Love me
b- Like me
c- Hate me
d- Think I am the ugliest boy on the face of the earth
I have relived the moment several times in my mind all the while trying to will my younger self to either not send the letter, or get rid of options "c" and "d". Alas, my younger self was unable to get the message, and the letter remains with option "d" circled.
At or around the age of 21, the frontal lobe starts to connect the dots. This also explains why I thought, up until that point, that my parents were idiots. While making decisions in my youth, my parents were always there to point out the pitfalls. Unfortunately, while they were talking, my mind turned on "Pop Goes the Weasel" which drowned out their advice. (By the way, you're welcome for getting "Pop Goes the Weasel" stuck in your head.)
As the age of 21 approached, the volume on the song varied from barely audible to overpowering. This explains walking in a lightning storm with my umbrella held high and getting struck by a tiny bolt of lightning, but it also explains why I did not go cliff diving from the very same spot that someone had died a year previous.
So now that we have gone through the excuse built in for those under 21, what is the excuse for those over 21? For example, when tragedy struck as a 39 year old father fell to his death while trying to catch a ball in Texas Ranger stadium, why on earth would another man days later even reach over the precipice? The man nearly met the same fate.
In all seriousness, we need to take a moment and turn down the music. Take a moment and consider the possible consequences of our actions. If we can all be a little more thoughtful, we might avoid some of the most serious of those consequences and maybe stick around on the third rock from the sun a little longer.