on statements of purpose

i have been to grad school so many times now, and written so so many different statements of purpose. why does god not give us homework? why is there no graduate school that he takes us into? where we each must write our own statements of purpose to get in? i am training myself now - to write my statement of purpose for life. yes, indeed it may change every month as my statements for school have. but i need a draft, no? before i can re-edit every month or year?