All I am is chemicals that work to influence my behaviour....
OR
All I am is a consciousness floating through space
Or
All I am is the work an words I put into the Earth

Whatever I am, it could never be put down on paper. The ideas I have and emotions I feel could never be expressed in a simple, corny catchphrase. 

But if, before I die, I manage to use these words to help someone understand themselves better then it would have been a worthwhile life....

...Although I'd love to be properly published too ;)