In the life-cycle of a company — be it a high tech startup or a paint manufacturer — the initial culture of the company is grown from the seed corn of the founders’ values.
The first challenge for any founder is to codify his/her values while recognizing that she/he owns the culture when the ink is still wet on the founding documents.
The culture is a living organism in much the same way that yeast provides life to dough and water to somehow magically become bread when presented to fire.
It is important to think about culture, but it will happen whether you think about it or not.
If you fail to think about and nurture your culture, then it will become whatever organism is blowing through the air. [The air is different in Silicon Valley than it is in, say, Austin By God Texas. Know this.]
In thinking about culture, go here: The Company Culture Series — a collection of 14 blog posts on the subject of culture.