Nobody hates me more than I; 
No enemy have I to-day 
That I so bravely must defy; 
There are no foes along my way, 
However bitter they may be, 
So powerful to injure me 
As I am, nor so quick to spoil 
The beauty of my bit of toil. 
 
Nobody harms me more than I; 
No one is meaner unto me; 
Of all the foes that pass me by 
I am the worst one that I see. 
I am the dangerous man to fear; 
I am the cause of sorrow here; 
Of all men 'gainst my hopes inclined 
I am myself the most unkind. 
 
I do more harmful things to me 
Than all the men who seem to hate; 
I am the fellow that should be 
More dreaded than the works of fate. 
I am the one that I must fight 
With all my will and all my might; 
My foes are better friends to me 
Than I have ever proved to be. 
 
I am the careless foe and mean; 
I am the selfish rival too; 
My enmity to me is seen 
In almost everything I do. 
More courage it requires to beat  
Myself, than all the foes I meet;  
I am more traitorous to me  
Than other men could ever be. 
 
In every struggle I have lost 
I am the one that was to blame; 
My weaknesses cannot be glossed 
By glib excuses. I was lame.  
I that would dare for fame or pelf  
Am far less daring with myself.  
I care not who my foes may be,  
I am my own worst enemy.
Edgar Albert Guest
http://www.poemhunter.com/poem/i-201/