And one of the things that I've discovered from this is that even something as seemingly mundane as the locomotive names and numbers has many little entertaining and interesting things in it, if you look at it closely enough and actually pay attention.
For instance, there's the "Atherton" (914), which is now sort of orphaned -- there's still an Atherton station, but it's not on the main schedule, because the weekday trains don't stop there any more.
Most of the trains have the same name as "their" station, but the "California" (916) doesn't; its station is "California Avenue" in Palo Alto, but I guess naming a locomotive after a street seemed silly.
There are a few Caltrain runs that go past San Jose south to Gilroy; I believe that's a somewhat recent addition. And this is echoed in the fact that the "Gilroy" (917), "San Martin" (921), and "Morgan Hill" (920) are near the top of the list by number.
And then, of course, there are the exceptions, that prove that things are never as simple as they appear at first glance. I always thought that all the locomotives were named after stations on the route, and two months of keeping notes didn't provide any counterevidence. But then today I happened to see the "County of San Mateo" (918), which is rather surprising, considering that I'd already noted down the "San Mateo" (902) several weeks earlier. I'm guessing there's a "County of Santa Clara" as well, probably numbered 919, but I haven't seen it.
I also haven't seen the "San Francisco" yet, either. Or, for that matter, a "San Jose". I wonder if maybe those were older locomotives that got retired, or something; I haven't seen numbers 900 and 901 yet, which are the ones I'd expect to have those names.