Is It? Poem by poor lil copycat

Is it perserverance
That makes us strive and achieve success?

Is it guilt
That makes us try again when we give up?

Is it practicality
That makes us learn from our mistakes?

Or is it pigheadedness
When we can't reach success

Or whining
When we feel like giving up

Or carelessness
When we make mistakes we shouldn't have?
~
Is it mercy
That makes a person end the life of a pained and ailing family member?