Yes, you do. The Tube is an amazing thing that goes almost everywhere, at least that a tourist needs to. Only occasionally have I had to resort to surface street buses, for places like Chelsea and the Regents Park Zoo, or Hampton Court, and I wish there were a diagram of the bus lines emblazoned on everything as there is of the Tube system.

We have our own light rail equivalent, and its system map (closer to a scale map than the Tube schematic is) looks like this:

As you can see, it's very primitive in its coverage by comparison. Unfortunately, I live as far south of Millbrae as the big line junction is north of it (someday the two south lines will loop around the Bay and connect, but I don't expect to live that long), and the place I need to get to is on the shoreline half an inch north of the "R" in "Embarcadero". So it's not going to do me much good on this occasion.