Parkinson's Law

"The demand upon a resource tends to expand to match the supply of the resource."

Or as tim ferris puts it 

"The complexity of a task expands to fill the time you alot it."

What this means. That a task will grow and grow, become more complex and more complex, the more time you give it or the longer leash you allow it. Example: Art. When you give a subject all the time in the world and all the resources and material and talent, you recieve something of near infinite complexity and varity. Counter example: my breakfast. Only given 5 minutes and a rather depleated pantry, peanut butter on toast.

Conculsion. Deadlines are a good thing. Otherwise thing tend to get out of hand.