Every time I open Google Maps it defaults to Palmer Ranch Healthcare & Rehabilitation.
How do I change this?
Click the "Gear" icon and choose "Search Settings".
Click "Location". Put in as detailed a location as you want. (A full address, a city and state, just a state, a country, etc.) Save.
Of course, this is tied to your Google account, so you'll need to be signed in for it to work.
More information from Google Maps Support: Location settings.
Since this question has been asked, the gear (for me at least) has become unavailable from my desktop web browser (Firefox), as has the location option under Search Settings. I was similarly being presented with a map centered on a location that wasn't relevant to me. To fix this problem, I hovered over the Your Location button (top-right button, grayed out, in the screenshot), pressed Update, temporarily gave access to my location to Google Maps, watched it recenter on my current location, then quit and reopened Firefox. Now, it centers on that location every time.
edit: I do have a Google account, but the location sticks in private browsing mode without my being logged in.
Do you (or did you) live or work at Palmer Ranch?
In the "old" Google Maps, you are able to set your Home and Work location:
If you are seeing the new Google Maps, you can get to the My places list by clicking on the cog wheel in the lower-right corner:
Now, I'm not convinced that Google Maps always uses your home as its default location. Another reason might be that Google thinks you're at Palmer Ranch you share their broadband connection/IP address.
For what it's worth, when I go to http://maps.google.com, I'm shown an overview map of Scandinavia (where I live).
I've always had Google Maps in my dock - easy to reach. But it kept opening to the city I used to live in. Even though I have Locations allowed in preferences and everywhere else I could think of, that wasn't working. And I don't want a Google account even though that might make it easier.
Well, I'd forgotten how I fixed that in the first place (it had been 12 years and Maps had evolved since then). All I did was to find my current location on Maps, then drag the URL to the dock. Now it opens at that location all the time, which is fine for most purposes for me since usually I want to find out where things are in my home city and for directions.
This will work only for the location you drag to the dock - I still can't get it to recognize my actual current location by default when I'm traveling no matter what preferences I allow - for that I have to click the wheel above the +/- zoom keys in the bottom right and tell it to use my current location. Then sometimes I have to specifically allow it. But at least it works without a Google account. And I use Duck-duck Go as my browser for privacy reasons.
Try this: if you are launching from a shortcut, just click the current location button in bottom right. If this is where you want Maps to open to, click the star button in the URL field and save as a favorite on toolbar or shortcuts menu. Done.
Create a shortcut on the Google page to have a click visual solution. When selected it brings up Google Maps so you can immediately add destination:
The following screeshot shows the Google Home page
The following screenshot shows "my home address" populated as the starting location with a blank destination