What's north of 101? The freeway generally runs north/south, so there'd be an east/west division.

Not in Mountain View & Sunnyvale. The peninsula curves around at the bottom, so north/south routes like 101, 82 (El Camino), and 280 go mostly east/west, with 85 branching off as a north/south spur. The "north" side of 101 is the side closest to the Bay, where Google is. Throws a lot of visitors for a loop.

Through the peninsula, especially in mountain view, it runs from southeast to northwest, north is towards the bay; south is towards the mountains. ca-85 is much closer to north/south through mountain view.

... until it's East/West from Saratoga on.

It gets more fun in the East Bay: you can be going Eastbound on 580 and Westbound on 80 at the same time (it's a shared road)!

101 is more East/West at that point, until it bends around the bay at Whipple.

That whole area is direction-impaired. The city of East Palo Alto is northwest of Palo Alto and in a different county!

Yeah, San Carlos air traffic controllers get pissy when you announce northbound over the 101 and you're really flying due west, with the sun in your face even.

If you really call it "the 101", they will peg you as being from SoCal.