Culture/Work ethic differences

MY company has two offices I travel between frequently. One is in Bothell, WA (where I am based) and one is in San Jose, CA (where I was born and raised & travel to about once a month). I am always shocked at the differences in the two offices.

Today I woke up "late" and got here at 8:15 am. I'm rushing around hoping to get set up in my cube before anyone notices. I walk in the door and no one is here. No secretary, no people, literally no one. The lights aren't even on and I have no idea how the lights here work...lol. So as I sit here at 8:25 I've heard the door open once or twice and I'm still working in the dark.

At the Bothell office, If i get there at 8:20 I'm one of the last ones there (out of 60-75 people). My co-worker buddies ask me if I'm "slacking" off.

How can one company have such different cultures?